GH-621: Minor cleanup and UI polishing in the Git open service.
GH-621: Minor cleanup and UI polishing in the Git open service.

 - Getting the currently selected repository is synchronous. 
 - Show the name of the currently active branches.

Signed-off-by: Akos Kitta <5adc53eb8928d8424ddf49bf102dba40aa33cffe@gmail.com>
hexa00/theia,epatpol/theia-1,epatpol/theia-1,hexa00/theia,epatpol/theia-1