Calls should match design

Epics: https://source.puri.sm/Librem5/use-cases/issues/1 https://source.puri.sm/Librem5/use-cases/issues/95

I know there are some design changed mentioned in your phone essentials list, but it would be useful to have a feature focused on implementing the complete calls application design.

• Phone Essentials List
• Make the party avatar display in a circle
• Change call window's multiple call features to match design
• Create new widget for number display in new call box
• Add dialed-number display to the pop-up dial pad in the call display
• Use new libhandy widget to lay out the Recent/Contacts/Dial pad parts of the main window
• Add new call icon