Now it's much clearer when looking at the code, that these routes are about
project-hosted tickets, and it's easier to see where the author-hosted
equivalents are missing.
There used to be project roles and repo roles, and they were separate. A while
ago I merged them, and there has been a single role system, used with both
repos and projects. However the table names were still "ProjectRole" and things
like that. This patch renames some tables to just refer to a "Role" because
there's only one kind of role system.
* When adding collaborators, you don't need a custom role. If you don't choose
one, a basic default "developer" role will be used
* If you don't assign a `ProjectCollabUser` role, a default "user" role is
assumed for logged in users, otherwise a "guest" role
* The "guest" role currently has no access at all
* Theoretically there may also be a "maintainer" role allowing project
sharers/maintainers to give maintainer-level access to more people, but right
now maintainer role would be the same as developer so I haven't added it yet
I used this chance to make some name changes, add some utils, tweak some
imports, remove more `setTitle`s and so on. I also made person, repo,
key and project creation forms verify CI-uniqueness.
