feat(json-rpc-engine): Export assertExpectedHooks (MetaMask#8747)

## Explanation

Exports the `assertExpectedHooks` utility which is helpful when creating
middlewares using `selectHooks`.

## References

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## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [ ] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/processes/updating-changelogs.md)
- [ ] I've introduced [breaking
changes](https://github.com/MetaMask/core/tree/main/docs/processes/breaking-changes.md)
in this PR and have prepared draft pull requests for clients and
consumer packages to resolve them

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: this is a surface-area change that only adds a new named
export and updates tests/changelog, with no behavioral changes to
request handling.
> 
> **Overview**
> Exposes the `assertExpectedHooks` helper as a public export from
`@metamask/json-rpc-engine/v2` (re-exported from `utils`).
> 
> Updates the v2 export snapshot test to include the new symbol and
notes the addition in the package changelog.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
d0b1873. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: FrederikBolding

packages/json-rpc-engine/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Export `assertExpectedHooks` utility ([#8747](https://github.com/MetaMask/core/pull/8747))
+
 ## [10.4.0]
 
 ### Added

packages/json-rpc-engine/src/v2/index.test.ts

@@ -9,6 +9,7 @@ describe('@metamask/json-rpc-engine/v2', () => {
         "JsonRpcServer",
         "MiddlewareContext",
         "asLegacyMiddleware",
+        "assertExpectedHooks",
         "createMethodMiddleware",
         "createOriginMiddleware",
         "createScaffoldMiddleware",

packages/json-rpc-engine/src/v2/index.ts

@@ -23,6 +23,7 @@ export {
   isRequest,
   JsonRpcEngineError,
   selectHooks,
+  assertExpectedHooks,
 } from './utils';
 export type {
   Json,