fix(releasing): Explicitly specify from which branch the release tag should be created from OCRVS-7369

[rikukissa]

A few small fixes here:

• Fix tagging mechanism so it always uses the branch defined as the "Branch to build from"
• Add descriptive commit messages to merge commits created by the pipeline
• Use the "Release tag" input as the tag to be created instead of reading a version from package.json
• Remove v___ prefix from tags to allow countries use whatever versioning scheme