Implement API Keys.

[chrisknoll]

Fixes#1884.

This PR introduces API Keys by creating a new controller (for create/list/delete operations), a database table and repository (sec_api_key), and migration scripts to define the tables (in a migration script and in baseline).

[chrisknoll]

@p-hoffmann : this PR is independent of #2523, but there is some overlap with base migrations and the JWT auth filter. I will merge this branch with the webapi-3.0 branch and then update this PR.

[chrisknoll]

The merge went through with no conflicts, and from my glance, I can see your changes were applied. This should be ready for review.

Note: while I made IT tests, i had to run them manually because for some reason the Embedded PG instance can not initilize on my local enviornment. I'm hoping the tests will run on the git action.

[chrisknoll]

Looks like tests pass and merge was clean, so @p-hoffmann if you want to give a quick review, this can be merged when ready.