* Fix memory leaks on fuzzer side in TestExt4Dxe, create common FreeAll
procedure.
* Extend GetPosition and SetPosition tests in TestExt4Dxe.
* Implements StriColl function from UnicodeCollation protocol for
userspace usage. Also provides replacement for origin unicode collation
driver functions Ext4InitialiseUnicodeCollation and Ext4StrCmpInsensitive
to use this StriColl implementation.