[ticket/12026] Correct path for template files

Correct path for template files in MCP and UCP modules, which are added
via extenstions

PHPBB3-12026
[ticket/12026] Remove phpbb root path

PHPBB3-12026
[ticket/12026] Remove root path, its prepended later

PHPBB3-12026
[ticket/12026] Add functional test for ucp extension module

PHPBB3-12026
Merge pull request #1 from nickvergessen/ticket/pico88/12026-2

Ticket/pico88/12026
Merge pull request #1879 from Pico88/ticket/12026

[ticket/12026] Correct path for template files