Automate Uploading MV3 build zips on the Releases pages from github

**What**: need to upload automatically MV3 builds on the Assets section from the [Releases page](https://github.com/MetaMask/metamask-extension/releases).


**How**: from @danjm 's comment: for the build to appear here, we need to modify `metamask-extension/.circleci/scripts/release-create-gh-release.sh`

### Details to add:

- exact specifications for workflow: push commit to RC, after beta build jobs there should be a release post job for the beta version
- determine how changelogs should work for beta versions (e.g. should a beta version contain the full versions changelog when it is first created? should the final version reference the intitial beta version changelog). Also, how to do changelog review / validation for beta changelogs?

Start with .circleci/scripts/release-create-gh-release.sh and inspect how MV3 beta builds and GitHub Releases are currently handled. Clarify the release post job after beta build jobs, then settle whether beta and final releases use full or referenced changelogs and how beta changelogs are reviewed; done means MV3 build zips appear in the release Assets section.

Written by the indexing model from the issue text.