Close#304.
Notes:
- This patch was made on top of Pleroma develop, so I created a separate cachex worker for request signature actions, instead of Akkoma's instance cache. If that is a merge blocker, I can attempt to move logic around for that.
- Regarding the `has_request_signatures: true -> false` state transition: I think that is a higher level thing (resetting instance state on new instance actor key) which is separate from the changes relevant to this one.
Co-authored-by: Luna <git@l4.pm>
Reviewed-on: AkkomaGang/akkoma#312
Co-authored-by: @luna@f.l4.pm <akkoma@l4.pm>
Co-committed-by: @luna@f.l4.pm <akkoma@l4.pm>
