Add lang packages and update HTTP URLs

[cretz]

What was changed

• Added needed lang-specific options to top of files
• Updated HTTP API annotations to have /api/v1/cloud/ prefix to make this easier to edge route when combined with other HTTP API on the same endpoint (this may change again)
• Added comment to top of cloud service saying it is experimental and may change incompatibly
• Couple of API linter ignores (these aren't really needed since this repo isn't merging into primary one yet, can remove if necessary)
• Fixed end-of-file newline inconsistency

Once merged, I can use git submodule/subtree to allow this to be referenced in the primary API repo. Do y'all want me to disable the buf-breaking check in code (to re-enable in later PR) or do y'all want to admin-bypass?