[chore] Migrate accounts to new table, relax uniqueness constraint of actor url and collections (#3928)

* [chore] Migrate accounts to new table, relax uniqueness constraint of actor url and collections

* fiddle with it! (that's what she said)

* remove unused cache fields

* sillyness

* fix tiny whoopsie

internal/processing/account/delete.go

@@ -528,7 +528,7 @@ func stubbifyAccount(account *gtsmodel.Account, origin string) []string {
 	account.Fields = nil
 	account.Note = ""
 	account.NoteRaw = ""
-	account.Memorial = util.Ptr(false)
+	account.MemorializedAt = never
 	account.AlsoKnownAsURIs = nil
 	account.MovedToURI = ""
 	account.Discoverable = util.Ptr(false)
@@ -546,7 +546,7 @@ func stubbifyAccount(account *gtsmodel.Account, origin string) []string {
 		"fields",
 		"note",
 		"note_raw",
-		"memorial",
+		"memorialized_at",
 		"also_known_as_uris",
 		"moved_to_uri",
 		"discoverable",