Bitbucket Cloud: Add Start Work Support

[sergeibbb]

1. Add support for seeing Bitbucket issues in Start Work.

2. Also make sure Bitbucket issues can be associated to branches using the "associate issue to branch" command in branch context menus.

3. Make sure that the associated issue is displayed on Home

4. Make sure the associated issue is displayed on Graph

(parent #3916, related (azure) #3979)

Testing notes

• select issue on StartWork and create a branch

  • link navigates to the issue page on Bitbucket
  

• associate issue to branch using context menus
  
  

• see the associated issue on Home (current and recent)

  • issue links navigate to the issue page on Bitbucket
  • issues go away from Home when the integration is disconnected
    
    

• see the associated issue on Graph

  • double click opens the issue page on Bitbucket