Simplify the long-press menu

[frandavid100]

This issue is related to #116 because it implies the workflow suggested there.

When you long-press an episode you get a lot of options that could be simplified:

In that screenshot:

• "Remove" deletes the file but leaves the episode in the playing queue.
• "Remove from queue" returns the file to the waiting list, but keeps the file in the phone.

If #116 is implemented neither of the above would make sense because being in the queue imply being downloaded, and the other way around. But we do need:

• A "Remove" option that completely deletes the file and makes the app forget about the episode. This should apply to items in the queue, waiting list or history. Also, in addition to a long-press action this could be triggered by swiping the episode away.
• An "Add to queue" option that takes items from the waiting list or the history and adds them to the bottom of the playing queue. Also, of course, sets them to be downloaded ASAP.
• Optionally some "Return to waiting list" and "Move to history" options for items in the queue. I don't think I would want these, though: once you move an episode to the queue you probably won't want to move it back unless you've lost your interest and don't want to listen to it anymore, in which case it would be simpler to just swipe it away and be done with it.
• "Mark as read" removes the "new" banner.
• "Mark as unread" adds it again.

I find these largely irrelevant and, unless I've misunderstood their function, I don't think they're worth two slots in the long-press menu.

Therefore, if you long-press an item in the playing queue I think that you should get these options:

• Play, which moves the episode to the top and starts playing it.
• Remove, already explained.

And if you long-press an item in the waiting list or history you should get:

• Play.
• Remove.
• Add to playing queue, which adds it to the bottom of the queue.

In addition to that, It could be useful to show these options as buttons on the bottom bar so that you can apply them to several items at once. Here's a quick mockup:

As you see the mockup shows several selected items and three buttons at the bottom bar, which correspond to Play, Remove and Add to queue.

[TomHennen]

So, I think we simplified the long press menu. There are currently only three items.

We're interested in doing a multi-select thing. #50 discusses this as well.