Add options to hide the vote and or comment buttons on content items

[olorin99]

Closes #134

[jwr1]

Thanks! Just a few points:

• I can't really imagine a case where having the option to control both the vote widgets and the comment widgets separately would be useful, so I'd say the option to hide them should be combined. Maybe something like "Hide action buttons" (hideActionButtons in the profile) or something similar.

• I believe some sort of description/subtitle would also be helpful for this setting. Maybe something like:

  Hides the action buttons (vote, boost, reply, etc.) below each post and comment. The controls are still accessible in the overflow menu. It is recommended to enable swipe gestures in unison with this setting.

• It looks like the icon for the new setting toggle needs to be updated, as it's just the same as the one above it.

• Can you also add the notification controls to hide when this settings is enabled?

• Can you add a reply button to the overflow menu? I'm just thinking if somebody did enable this setting but did not enable swipe gestures, then there'd be no way to reply to anything.

[olorin99]

Moved the inkwell that opens the overflow menu into content_item since onReply sets the content item state. The reply action won't be available from a collapsed comments overflow menu but I figure users shouldn't be able to reply to hidden content anyway so its alright.