[chore] reformat GetAccount() functionality, support updating accounts based on last_fetch (#1411)

* reformat GetAccount() functionality, and add UpdateAccount() function.

* use fetched_at instead of last_webfingered_at

* catch local "not found" errors. small formatting / error string changes

* remove now unused error type

* return nil when wrapping nil error

* update expected error messages

* return correct url for foss satan webfinger

* add AP model for Some_User

* normalize local domain

* return notretrievable where appropriate

* expose NewErrNotRetrievable

* ensure webfinger for new accounts searched by uri

* update local account short circuit

* allow enrich to fail for already-known accounts

* remove unused LastWebfingeredAt

* expose test maps on mock http client

* update Update test

* reformat GetAccount() functionality, and add UpdateAccount() function.

* use fetched_at instead of last_webfingered_at

* catch local "not found" errors. small formatting / error string changes

* remove nil error checks (we shouldn't be passing nil errors to newError() initializers)

* remove mutex unlock on transport init fail (it hasn't yet been locked!)

* woops add back the error wrapping to use ErrNotRetrievable

* caches were never being started... 🙈

---------

Signed-off-by: kim <grufwub@gmail.com>
Co-authored-by: tsmethurst <tobi.smethurst@protonmail.com>

internal/federation/handshake.go

@@ -17,12 +17,3 @@
 */
 
 package federation
-
-import (
-	"context"
-	"net/url"
-)
-
-func (f *federator) Handshaking(ctx context.Context, username string, remoteAccountID *url.URL) bool {
-	return f.dereferencer.Handshaking(ctx, username, remoteAccountID)
-}