[WIP][FEATURE] added delete icon on toolbar for some pages

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

instanceName should be either 'undefined' or null by default