Draft: Release client-go 2.0

this MR merges the release-client-2.0 branch into main to perform the 2.0 release.

Not only does this merge the MRs that we've added to the release-client-2.0 branch, but it also ensures the presence of a comprehensive migrate note document, and updates the README to point to the new migration guide

Note: Squash is NOT enabled on this MR, and make sure to not enable it when merging!

⚠️ - Make sure to include BREAKING CHANGE: Release 2.0 in the merge commit footer to trigger the new version upgrade!