Fix: make the play actions consistent

[marcelveldt]

Clicking an item was a bit inconsistent throughout the app, this is now solved

• Show play button to direct play an item
• Click on item --> show details
• Click on list item in albums or playlist tracks --> play item
• Click on menu / right click / touch hold --> show contextmenu
• Play button is shown on mouseover, on mobile devices the play button will always be shown