Add group support

[diorcety]

Pull Request type

Please check the type of change your PR introduces:

• [ ] Bugfix
• [x] Feature
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no API changes)
• [ ] Build-related changes
• [ ] Documentation content changes
• [ ] Other (please describe):

What is the current behavior?

Issue Number: #103

What is the new behavior?

• Add new create group input
• Allow to drag & drop member across groups

Does this introduce a breaking change?

• [ ] Yes
• [x] No

Other information

[dec0dOS]

@diorcety, thanks for the work on this. I’ll review it when I get a chance.