Refactor Javascript modules
Split up the, at this point quite big, ext.wikispeech. Some methods
were also moved from ext.wikispeech.selectionPlayer. The new modules
are both smaller and have a more specific tasks.
The modules are now (all starting with ext.wikispeech):
- main - initializes the rest of the modules, when approriate.
- storage - holds utterances and does calculation for utterances and DOM.
- player - playback control.
- selectionPlayer - logic for reciting selected text.
- ui - adds GUI and handles user input.
- highlighter - higlights text when reciting.
- util - functions that are used by multiple modules without having a strong connection to any of them.
A couple of failing tests are now fixed, possibly as a result over
earlier patches.
Bug: T182205
Bug: T174799
Change-Id: Ic199134bf171ba778048f2461cce1d9a61ff5433