refactor: address tech debt for chain agnostic permission code repeated on extension and mobile codebases (#6225)

## Explanation

While working on [adding Multichain API to Flask on
mobile](MetaMask/metamask-mobile#14756), some
code that is common to the browser extension repository was also created
on the mobile codebase, namely [these permissions
utilities](https://github.com/MetaMask/metamask-mobile/blob/main/app/util/permissions/index.ts)
which are also present in the `extension` [metamask-controller
module](https://github.com/MetaMask/metamask-extension/blob/main/app/scripts/metamask-controller.js):

- `getCaip25PermissionFromLegacyPermissions`
- `requestPermittedChainsPermissionIncremental`

The work proposed in this pull request migrates these common
functionalities onto our `@metamask/chain-agnostic-permissions` package,
so that they can be imported on both `mobile` and `extension` to be
used.

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## References

* Fixes MetaMask/MetaMask-planning#4899
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## Changelog

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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
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

Author: ffmcgee725

packages/chain-agnostic-permission/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Added `getCaip25PermissionFromLegacyPermissions` and `requestPermittedChainsPermissionIncremental` misc functions. ([#6225](https://github.com/MetaMask/core/pull/6225))
+
 ### Changed
 
 - Bump `@metamask/controller-utils` from `^11.10.0` to `^11.11.0` ([#6069](https://github.com/MetaMask/core/pull/6069))