Document uniqueness of name on Organization and User

[nicksnyder]

Document the uniqueness of the name field on the field itself.

Closes #2

[bufdev]

I could go either way on the meat of this - moving the unique fields above the create_time and update_time. The thinking was that the "standard resource fields", namely id, create_time, update_time, all come first, where the resource-specific fields come later.

If we did do this, you'd need to update the comments globally, not just for one package (ie all of the module package needs to be updated as well). However, I do think having the uniqueness constraints at the top level on a message is nice, so we could perhaps have them both on the field and at the top level.

[nicksnyder]

However, I do think having the uniqueness constraints at the top level on a message is nice, so we could perhaps have them both on the field and at the top level.

I updated this PR to just be about copying the documentation for uniqueness on the field itself. Can consider re-ordering fields in a separate PR.

[nicksnyder]

The thinking was that the "standard resource fields", namely id, create_time, update_time, all come first, where the resource-specific fields come later.

Yeah, I figured.

If we did do this, you'd need to update the comments globally, not just for one package (ie all of the module package needs to be updated as well).

Not sure what you mean here. It isn't clear to me that we would want to re-order name field in branch, module, tag because those are only identifiers within some context (user/org/module), and not really equivalent to an id or name in the same sense that it is for User and Organization.

In any case, after some reflection, I think adding docs to the field is sufficient (which is what this PR diff now is), and we don't need to go so far as changing the order of or renaming the fields.

[bufdev]

Not sure what you mean here.

Yea looking into it, we actually do have "uniqueness" comments on the module package types, I wasn't paying attention closely enough. This LGTM.