feat!: Add hooks to allow app modules to add things to state-sync (#10961)

## Description

Closes: #7340

- Support registering multiple snapshotters in snapshot manager.
- Append the extension snapshotters to existing snapshot stream.

~TODO: testing.~
- existing tests are fixed






---

### Author Checklist

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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/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)
- [ ] 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
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- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

server/mock/store.go

@@ -3,8 +3,10 @@ package mock
 import (
 	"io"
 
+	protoio "github.com/gogo/protobuf/io"
 	dbm "github.com/tendermint/tm-db"
 
+	snapshottypes "github.com/cosmos/cosmos-sdk/snapshots/types"
 	storetypes "github.com/cosmos/cosmos-sdk/store/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
@@ -122,13 +124,13 @@ func (ms multiStore) SetInitialVersion(version int64) error {
 	panic("not implemented")
 }
 
-func (ms multiStore) Snapshot(height uint64, format uint32) (<-chan io.ReadCloser, error) {
+func (ms multiStore) Snapshot(height uint64, protoWriter protoio.Writer) error {
 	panic("not implemented")
 }
 
 func (ms multiStore) Restore(
-	height uint64, format uint32, chunks <-chan io.ReadCloser, ready chan<- struct{},
-) error {
+	height uint64, format uint32, protoReader protoio.Reader,
+) (snapshottypes.SnapshotItem, error) {
 	panic("not implemented")
 }