Remove unused icons
Remove fill none from icons
Rename some icons

- add possibility to allow execution of the button's routine besides triggering
`toolbarButtonClicked` API event
- keep backwards compatibility
- get rid of `ToolbarButton`

* feat(toolbox) allow any toolbox button to be displayed as main

fixes the previous behaviour where only a certain set of buttons were whitelisted for being displayed in the main toolbar

* code review

* code review - fix avatar icon position