[ticket/11481] Move feed factory to own file

PHPBB3-11481
[ticket/11481] Move feed base to own file

PHPBB3-11481
[ticket/11481] Move feed post base to own file

PHPBB3-11481
[ticket/11481] Move feed topic base to own file

PHPBB3-11481
[ticket/11481] Move overall feed to own file

PHPBB3-11481
[ticket/11481] Move forum feed to own file

PHPBB3-11481
[ticket/11481] Move topic feed to own file

PHPBB3-11481
[ticket/11481] Move forums feed to own file

PHPBB3-11481
[ticket/11481] Move news feed to own file

PHPBB3-11481
[ticket/11481] Move topics feed to own file

PHPBB3-11481
[ticket/11481] Move active topics feed to own file

PHPBB3-11481
[ticket/11481] Move functions from feed into helper class

PHPBB3-11481
[ticket/11481] Use container for all classes and inject dependencies

PHPBB3-11481
[ticket/11481] Remove globals and use dependency injection instead

PHPBB3-11481
[ticket/11481] Move prepended slash from calls into function

PHPBB3-11481
Merge remote-tracking branch 'remotes/nickv/ticket/11481' into develop

# By Joas Schilling
# Via Joas Schilling
* remotes/nickv/ticket/11481:
  [ticket/11481] Move prepended slash from calls into function
  [ticket/11481] Remove globals and use dependency injection instead
  [ticket/11481] Use container for all classes and inject dependencies
  [ticket/11481] Move functions from feed into helper class
  [ticket/11481] Move active topics feed to own file
  [ticket/11481] Move topics feed to own file
  [ticket/11481] Move news feed to own file
  [ticket/11481] Move forums feed to own file
  [ticket/11481] Move topic feed to own file
  [ticket/11481] Move forum feed to own file
  [ticket/11481] Move overall feed to own file
  [ticket/11481] Move feed topic base to own file
  [ticket/11481] Move feed post base to own file
  [ticket/11481] Move feed base to own file
  [ticket/11481] Move feed factory to own file