Lets introduce a new helper function,
`CreateDeclarativeRepoWithOptions`! This is almost the same as the
existing `CreateDeclarativeRepo` helper, but instead of taking a list of
random parameters the author thought of at the time of its introduction,
it takes a `DeclarativeRepoOptions` struct, with optional members.
This makes it easier to extend the function, as new members can be added
without breaking or having to update existing callsites, as long as the
newly added members default to compatible values.
`CreateDeclarativeRepo` is then reimplemented on top of the new
function. Callsites aren't updated yet, we can do that organically,
whenever touching code that uses the older function.
No new functionality is introduced just yet, this is merely a refactor.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>