Fix custom symbol pane for Persian language
The symbol pane used to be refered by the path from the keyboard's data dir, because that's where the language plugins were installed. But since the restructure in b7884136 ("Switch the plugin installation path to Lomiri"), that's no longer the case.
Call Qt.resolvedUrl()
on the layout file itself instead to solve the
path relative to the layout file, and fix how the symbol layout file
refers to the internal of the keyboard.
Edited by Ratchanan Srirattanamet