feat: Replace ad hoc auth header with internet standard bearer token auth header

[SleeplessOne1917]

Does as the title says

The only file that was changed that wasn't a Cargo.toml/lock file was the session middleware. All the other changes were from running cargo fmt to try to satisfy the woodpecker build to no avail.

[Nutomic]

I already implemented this in #3818, but your change is much cleaner so lets use that.

To make the API tests pass you have to set the correct header there, analogous to this change from my PR: b2bacd1

[dessalines]

Sweet, thx.