JamiIdentifier: display issue when choosing a username

Steps to reproduce:

1. Create an account without a username
2. Click on the "choose username" button in the JamiIdentifier
3. Click outside of JamiIdentifier

Display issues:

• The hash sould not be elided and the rectangle should resize to the length of the hash.
• The TextEdit should not be this huge and should not be cropped.
• This should not be displayed. When you click outside it should quit the username choosing and return to the identifier display with the hash.

assigned to @cberthet

Settings, General, Appearance, Text zoom level = 50

Settings, General, Appearance, Text zoom level = 200

closed

mentioned in commit adfafd9d