[WIP] Clean up JavaScript scripts

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #5
| License       | MIT
| Doc PR        | -

### Todo

 - [x] Rename files
 - [ ] Update CS

        - [x] `admintree.js`
        - [ ] `selecttree.js`
 - [ ] Add default values

        - [ ] `admintree.js`
        - [ ] `selecttree.js`

 - [ ] Concat name on 18th character and show full name in tooltip
 - [ ] Do not show link if not editable