[WIP] Feature/type overlay

added account category entity and API
integrated category selection / overlay to choose / add and edit categories

__Tasks:__

- [ ] create orm xml and entity
- [ ] create rest controller
- [ ] integrate select and overlay
- [ ] test coverage
- [ ] gather feedback for my changes

__Informations:__

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Tests pass?   | yes
| Fixed tickets | none
| Doc           | none