[ticket/13119] Add events to MCP's ban module

PHPBB3-13119
[ticket/13119] Add events to ACP's ban module

PHPBB3-13119
[ticket/13119] Remove unused globals and use the request class

PHPBB3-13119
Merge remote-tracking branch 'nickvergessen/ticket/13119' into develop-ascraeus

* nickvergessen/ticket/13119:
  [ticket/13119] Remove unused globals and use the request class
  [ticket/13119] Add events to ACP's ban module
  [ticket/13119] Add events to MCP's ban module