[pvr] refactor advanced setting showepginfoonselect to setting

This removes the advanced setting showepginfoonselect and adds it to
settings, so users can change it within the gui. In addition, the
setting is extended and you can now select the following values:

* Show context menu
* Switch to channel
* Show information
* Record
[pvr] re-order epg context menu (move switch channel to top)