[DevToys 2.0] Added CheckBox and ToggleSwitch (#841)
* [DevToys 2.0] Added context menu and popup system.
* Fixed bug in TextBox involving Clipboard usage
* Remove duplicates in CSS file.
* Removed some duplicated code
* [DevToys 2.0] Added search bar + keyboard navigation in context menu
* [DevToys 2.0] Added CheckBox and ToggleSwitch
* tiny fix
* Addressed feedback
