Refactoring (List): final step

[Konstiman]

This PR introduces the last part of the List component refactoring: the transition to a single List component and the legacy code removal.

The new code is now independent of the MODERN_FRONTEND flag: the app always builds with the new code.

Main features:

Redux:

• New RESIZE action for handling the page resize

Components:

• The list is now one single component
• Moved the remaining HTML from the .handlebars to the subcomponents
• Minor fixes and code improvements
• Removed warns from the actions triggered by new code

Legacy code:

• Deleted all of the code that ran conditionally if the modern frontend flag was off
• Deleted all the list .handlebars templates (they were all refactored into the .jsx templates)

Tests:

• Since the structure changed, a lot of tests had to be modified

Known bugs:

none yet