feat: upgrade tdf clients to rewrap v2 proto structure

[jakedoublev]

WIP: upgrade signed request body to v2 structure (driven by protos) that allows bulk functionality and errors

[github-actions]

If these changes look good, signoff on them with:

git pull && git commit --amend --signoff && git push --force-with-lease origin

If they aren't any good, please remove them with:

git pull && git reset --hard HEAD~1 && git push --force-with-lease origin

[jakedoublev]

closing in favor of #758