[ticket/13063] Introduces a new \phpbb\routing\router class

PHPBB3-13063
[ticket/13063] Adds Twig routing extension

PHPBB3-13063
[ticket/13063] Remove kernel_request_subscriber service definition

PHPBB3-13063
[ticket/13063] Fix tests after rebase

PHPBB3-13063
[ticket/13063] Fix coding style

PHPBB3-13063
[ticket/13063] Fix functional tests errors

PHPBB3-13063
Merge pull request #2957 from Nicofuma/ticket/13063

[ticket/13063] Introduces a new \phpbb\routing\router class