* [chore] Remove years from all license headers
Years or year ranges aren't required in license headers. Many projects
have removed them in recent years and it avoids a bit of yearly toil.
In many cases our copyright claim was also a bit dodgy since we added
the 2021-2023 header to files created after 2021 but you can't claim
copyright into the past that way.
* [chore] Add license header check
This ensures a license header is always added to any new file. This
avoids maintainers/reviewers needing to remember to check for and ask
for it in case a contribution doesn't include it.
* [chore] Add missing license headers
* [chore] Further updates to license header
* Use the more common // indentend comment format
* Remove the hack we had for the linter now that we use the // format
* Add SPDX license identifier
* tidy up context keys, add otherInvolvedIRIs
* add ReplyToable interface
* skip block check if we own the requesting domain
* add block check for other involved IRIs
* use cacheable status fetch
* remove unused ContextActivity
* remove unused ContextActivity
* add helper for unique URIs
* check through CCs and clean slice
* add GetAccountIDForStatusURI
* add GetAccountIDForAccountURI
* check blocks on involved account
* add statuses to tests
* add some blocked tests
* go fmt
* extract Tos as well as CCs
* test PostInboxRequestBodyHook
* add some more testActivities
* deduplicate involvedAccountIDs
* go fmt
* use cacheable db functions, remove new functions
Daenney
tobi