Code Formats, Nits & Unused Func/Var deletions (#15286)

* _ to unused func options

* rm useless brakets

* rm trifial non used models functions

* rm dead code

* rm dead global vars

* fix routers/api/v1/repo/issue.go

* dont overload import module

modules/storage/storage.go

@@ -19,8 +19,6 @@ import (
 var (
 	// ErrURLNotSupported represents url is not supported
 	ErrURLNotSupported = errors.New("url method not supported")
-	// ErrIterateObjectsNotSupported represents IterateObjects not supported
-	ErrIterateObjectsNotSupported = errors.New("iterateObjects method not supported")
 )
 
 // ErrInvalidConfiguration is called when there is invalid configuration for a storage