Fix issue with EasyCallback which would cause it to return failure and success (I think) and fix infinite loading state on groups

Make retrofit callbacks better by simplifiing them so that all errors are handled in the onAllError block.

* Integrate Settings activity in navigation drawer
* Implement basic Settings activity with theme section (dark/light
theme, primary color and accent color preferences)
* Add/Update new styles for ATE

Update plugin. Make it where issue id title uses the internal id. Allow user to control if they are viewing open or closed issues, and allow user to control if they are viewing open, merged, closed, or all merge requests. Add activity transition between list of groups and group detail.