[chore] Refactor account deleting/block logic, tidy up some other processing things (#1599)

* start refactoring account deletion

* update to use state.DB

* further messing about

* some more tidying up

* more tidying, cleaning, nice-making

* further adventures in refactoring and the woes of technical debt

* update fr accept/reject

* poking + prodding

* fix up deleting

* create fave uri

* don't log using requestingAccount.ID because it might be nil

* move getBookmarks function

* use exists query to check for status bookmark

* use deletenotifications func

* fiddle

* delete follow request notif

* split up some db functions

* Fix possible nil pointer panic

* fix more possible nil pointers

* fix license headers

* warn when follow missing (target) account

* return wrapped err when bookmark/fave models can't be retrieved

* simplify self account delete

* warn log likely race condition

* de-sillify status delete loop

* move error check due north

* warn when unfollowSideEffects has no target account

* warn when no boost account is found

* warn + dump follow when no account

* more warnings

* warn on fave account not set

* move for loop inside anonymous function

* fix funky logic

* don't remove mutual account items on block;
do make sure unfollow occurs in both directions!

internal/api/model/account.go

@@ -206,9 +206,6 @@ type AccountFollowRequest struct {
 type AccountDeleteRequest struct {
 	// Password of the account's user, for confirmation.
 	Password string `form:"password" json:"password" xml:"password"`
-	// The origin of the delete account request.
-	// Can be the ID of the account owner, or the ID of an admin account.
-	DeleteOriginID string `form:"-" json:"-" xml:"-"`
 }
 
 // AccountRole models the role of an account.