Aegis: Improve entry group management

[alexbakker]

Support for entry groups is fairly basic currently.

• Create a separate DatabaseEntryGroup object for groups
  
  
  
  • Fields: UUID, Name
  
  
• DatabaseEntry
  
  
  
  • Refer to groups by their UUID instead of their Name
  
  
  • Allow assigning an entry to multiple groups
  
  
• GroupManagerActivity
  
  
  
  • Require the user to click a "Save" button before actually saving any changes
  
  
  • Warn about unsaved changes by showing a "Discard changes?" dialog
  
  
  • Support custom group ordering (with alphabetic ordering as default)
  
  
  • Add the ability to rename groups
  
  
• MainActivity
  
  
  
  • Support selecting multiple groups to filter on
  
  
  • Persist the selected group filter
  
  

[rmunozrodriguez]

Persist the selected group filter on exit would be great.

[claytondaley]

I'd really like a top-level groups UI element (i.e. two clicks to pick a group vs 3) to complement the "persist group" suggestion above. I went back to "Authenticator Plus" to see how they do it (atrocious security but I needed groups badly) and I also feel like their menu icon is less fiddly which seems to be due to (1) ~2x the real estate and (2) on the left. I find the smaller icon jammed up against the right edge (i.e. the lip of my case) a lot harder to use.