feat!: add error handling to staking hooks (#9571)

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## Description

- Adds error handling for staking hooks

<!-- Add a description of the changes that this PR introduces and the files that
are the most critical to review. -->

---

### Author Checklist

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please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [x] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [x] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

x/slashing/keeper/hooks.go

@@ -9,7 +9,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/slashing/types"
 )
 
-func (k Keeper) AfterValidatorBonded(ctx sdk.Context, address sdk.ConsAddress, _ sdk.ValAddress) {
+func (k Keeper) AfterValidatorBonded(ctx sdk.Context, address sdk.ConsAddress, _ sdk.ValAddress) error {
 	// Update the signing info start height or create a new signing info
 	_, found := k.GetValidatorSigningInfo(ctx, address)
 	if !found {
@@ -23,6 +23,8 @@ func (k Keeper) AfterValidatorBonded(ctx sdk.Context, address sdk.ConsAddress, _
 		)
 		k.SetValidatorSigningInfo(ctx, address, signingInfo)
 	}
+
+	return nil
 }
 
 // AfterValidatorCreated adds the address-pubkey relation when a validator is created.
@@ -32,14 +34,14 @@ func (k Keeper) AfterValidatorCreated(ctx sdk.Context, valAddr sdk.ValAddress) e
 	if err != nil {
 		return err
 	}
-	k.AddPubkey(ctx, consPk)
 
-	return nil
+	return k.AddPubkey(ctx, consPk)
 }
 
 // AfterValidatorRemoved deletes the address-pubkey relation when a validator is removed,
-func (k Keeper) AfterValidatorRemoved(ctx sdk.Context, address sdk.ConsAddress) {
+func (k Keeper) AfterValidatorRemoved(ctx sdk.Context, address sdk.ConsAddress) error {
 	k.deleteAddrPubkeyRelation(ctx, crypto.Address(address))
+	return nil
 }
 
 // Hooks wrapper struct for slashing keeper
@@ -55,24 +57,34 @@ func (k Keeper) Hooks() Hooks {
 }
 
 // Implements sdk.ValidatorHooks
-func (h Hooks) AfterValidatorBonded(ctx sdk.Context, consAddr sdk.ConsAddress, valAddr sdk.ValAddress) {
-	h.k.AfterValidatorBonded(ctx, consAddr, valAddr)
+func (h Hooks) AfterValidatorBonded(ctx sdk.Context, consAddr sdk.ConsAddress, valAddr sdk.ValAddress) error {
+	return h.k.AfterValidatorBonded(ctx, consAddr, valAddr)
 }
 
 // Implements sdk.ValidatorHooks
-func (h Hooks) AfterValidatorRemoved(ctx sdk.Context, consAddr sdk.ConsAddress, _ sdk.ValAddress) {
-	h.k.AfterValidatorRemoved(ctx, consAddr)
+func (h Hooks) AfterValidatorRemoved(ctx sdk.Context, consAddr sdk.ConsAddress, _ sdk.ValAddress) error {
+	return h.k.AfterValidatorRemoved(ctx, consAddr)
 }
 
 // Implements sdk.ValidatorHooks
-func (h Hooks) AfterValidatorCreated(ctx sdk.Context, valAddr sdk.ValAddress) {
-	h.k.AfterValidatorCreated(ctx, valAddr)
+func (h Hooks) AfterValidatorCreated(ctx sdk.Context, valAddr sdk.ValAddress) error {
+	return h.k.AfterValidatorCreated(ctx, valAddr)
 }
 
-func (h Hooks) AfterValidatorBeginUnbonding(_ sdk.Context, _ sdk.ConsAddress, _ sdk.ValAddress)  {}
-func (h Hooks) BeforeValidatorModified(_ sdk.Context, _ sdk.ValAddress)                          {}
-func (h Hooks) BeforeDelegationCreated(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress)        {}
-func (h Hooks) BeforeDelegationSharesModified(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress) {}
-func (h Hooks) BeforeDelegationRemoved(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress)        {}
-func (h Hooks) AfterDelegationModified(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress)        {}
-func (h Hooks) BeforeValidatorSlashed(_ sdk.Context, _ sdk.ValAddress, _ sdk.Dec)                {}
+func (h Hooks) AfterValidatorBeginUnbonding(_ sdk.Context, _ sdk.ConsAddress, _ sdk.ValAddress) error {
+	return nil
+}
+func (h Hooks) BeforeValidatorModified(_ sdk.Context, _ sdk.ValAddress) error { return nil }
+func (h Hooks) BeforeDelegationCreated(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress) error {
+	return nil
+}
+func (h Hooks) BeforeDelegationSharesModified(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress) error {
+	return nil
+}
+func (h Hooks) BeforeDelegationRemoved(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress) error {
+	return nil
+}
+func (h Hooks) AfterDelegationModified(_ sdk.Context, _ sdk.AccAddress, _ sdk.ValAddress) error {
+	return nil
+}
+func (h Hooks) BeforeValidatorSlashed(_ sdk.Context, _ sdk.ValAddress, _ sdk.Dec) error { return nil }