[ticket/11444] Moving the in-board notifications to a method class

Currently the in-board method for the notifications is hardcoded and
cannot be disabled. This method should be in his own class extending
`phpbb\notification\method\method_interface`.

It also add the possibility, for each method, to be enabled by default (ie:
no entry in the DB => notification enabled).

https://tracker.phpbb.com/browse/PHPBB3-11444
https://tracker.phpbb.com/browse/PHPBB3-11967

PHPBB3-11444
[ticket/11444] Adding migration and updating install datas

PHPBB3-11444
[ticket/11444] Add configuration value

PHPBB3-11444
[ticket/11444] Add "support" for prototype scope in mock_container_builder

PHPBB3-11444
[ticket/11444] Update functionnal tests

PHPBB3-11444
[ticket/11444] Update unit tests

PHPBB3-11444
[ticket/11444] Add missing config value in schema_data.sql

PHPBB3-11444
[ticket/11444] Fix unit tests

PHPBB3-11444
[ticket/11444] Add in_board method for unit tests

PHPBB3-11444
[ticket/11444] Fix unit tests

PHPBB3-11444
[ticket/11444] Fix add/delete subscription without method

PHPBB3-11444
[ticket/11444] Fix unit tests

PHPBB3-11444
[ticket/11444] Don't add subscriptions to disabled default methods

PHPBB3-11444
[ticket/11444] Correct package declaration

PHPBB3-11444
[ticket/11444] Fix documentation

PHPBB3-11444
[ticket/11444] Update langage

PHPBB3-11444
[ticket/11444] Rename 'in-board' into 'board'

PHPBB3-11444
[ticket/11444] Update the tests to use 'board' instead of 'in_board'

PHPBB3-11444
[ticket/11444] Fix unit test (wrong config var)

PHPBB3-11444
[ticket/11444] Disable ucp_module when board notifications are disabled

PHPBB3-11444