[FEATURE] improved item table and editable row component

__Tasks:__
- [x] done
- [ ] got feedback

__Informations:__

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Tests pass?   | yes
| Fixed tickets | none
| Doc           | none

replace the whole block by:
```
if (!data) {
    data = ''
}
this.$el.data({
    'value': data
}).trigger('data-changed');