Create Group functionality added

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[x] Apply the
AndroidStyle.xmlstyle template to your code in Android Studio. -
[x] Run the unit tests with
./gradlew checkto make sure you didn't break anything. -
[x] If you have multiple commits please combine them into one commit by squashing them.
Looking great @miPlodder @therajanmaurya what do you think?
@therajanmaurya @awasum I have to push one functionality more to this PR, which I will be doing today. After that this PR will be Ready for Review.
Great work @miPlodder ...Keep up.
@therajanmaurya Please review this PR.
@miPlodder @awasum @therajanmaurya The edit functionality has not been implemented in this PR although the APIs are ready and also there is no edit or delete option whenever the user adds leaders or members mistakenly. I would like to work on it with some UI refactoring.
@jawidMuhammadi If you need any help or if you could divide work, I'd be ready to volunteer. Let me know. :)
@anubhav11march Yeah sure, thank you so much, let me see.
@miPlodder this PR can be closed safely. PR #101 has been created on top of this PR and it has been already merged.