refactor: remove simapp references from x/bank and x/slashing tests (#12897)

## Description

There are still some references to simapp in `x/bank` and `x/slashing`.  This patch removes them.  Somewhat related to forming tests also:

- Flags `LegacySubspace exported.Subspace` as ``optional:"true"`` since x/params is moving to deprecation 



---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

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

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
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/auth/module.go

@@ -5,13 +5,14 @@ import (
 	"encoding/json"
 	"fmt"
 
-	modulev1 "cosmossdk.io/api/cosmos/auth/module/v1"
-	"cosmossdk.io/core/appmodule"
-	"cosmossdk.io/depinject"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/runtime"
 	"github.com/spf13/cobra"
 	abci "github.com/tendermint/tendermint/abci/types"
 
+	modulev1 "cosmossdk.io/api/cosmos/auth/module/v1"
+	"cosmossdk.io/core/appmodule"
+	"cosmossdk.io/depinject"
+
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
@@ -199,7 +200,7 @@ type authInputs struct {
 	Cdc    codec.Codec
 
 	// LegacySubspace is used solely for migration of x/params managed parameters
-	LegacySubspace exported.Subspace
+	LegacySubspace exported.Subspace `optional:"true"`
 }
 
 type authOutputs struct {