Register display name from settings instead of hardcoding

[RicardoMusch]

Reopening this pull request.

Changes:

• Renamed app commands to breakdown2 since naming it breakdown seems to cause conflicts with the older breakdown app in case both are used in the same engine config.
• Added display_name setting to rename the app as desired
• Changed unit tests to reflect changes in command name and display name.
• The default display_name is Scene Breakdown2. When registering the panel the registration will register {display_name} and append three dots as is usual for Toolkit apps, resulting in {display_name}....

[rob-aitchison]

Hi @RicardoMusch , I have just fixed-up my branch so PR #44 is now going to be reviewed with all of these changes included. Thanks as always for your help and participation - cheers!

[RicardoMusch]

Thanks! Sorry did not yet have time to address changes.