api: add schema and stubs for bootstrap token CRUD

[mikemorris]

Changes proposed in this PR:

• Add initial schema and stubs for bootstrap token CRUD operations.
• Add a new make gen command to install oapi-codegen if necessary and regenerate generated code and golden test files.

How I've tested this PR:

Running make gen and go test ./... in internal/api/v1 to make sure I didn't accidentally break anything.

How I expect reviewers to test this PR:

Is there a less verbose way to nest sub-paths like the token CRUD operations under /gateway/{name}/ in the OpenAPI schema?

Checklist:

• Tests added
• CHANGELOG entry added

  Run make changelog-entry for guidance in authoring a changelog entry, and
  commit the resulting file, which should have a name matching your PR number.
  Entries should use imperative present tense (e.g. Add support for...)

[sarahalsmiller]

👏

[sarahalsmiller]

Should we have a retrieval endpoint or should we assume that the token is only available on generation? I'm not sure how secure we need these to be.

[mikemorris]

Yea, I wasn't sure about this either, thoughts @andrewstucki?

[mikemorris]

Will keep this for now and remove later if not needed (assuming all of this may be subject to change depending on how our VM/API work evolves), agreed it might be useful for returning metadata about a token like TTL, revocation status, etc.

[sarahalsmiller]

Stubs look good to me, just the one question about if we should have the GET endpoint for tokens. We might want to keep it and have it just return some metadata about the tokens, not sure.