* Registered parameter types go in their own files
* Moves [int, float] item definitions outside `WidgetParameterItem`
* Moves [int, float] parameter definitions outside `WidgetParameterItem`
* Allow registering ParameterItems for easy parameter defs
* Finalizes moving simple parameters to their own files
* removes accidentally committed file
* Provides class qualnames in rst
* Address docstring build issues
* Address recent review comments
- `registerParameterItemType`:
* added to docs and parametertree.__init__
* Remove unsed PARAM_TYPES global
* Hyperlink to `registerParameterType`
- parameter tree rst:
* Alphabetize entries
* Rebuild RST without fully qualified class name
* Add note at file header that it is auto generated
* Remove spurious space during rst doc creation
* Ensure created/modified files end with newline
* Address CodeQL warnings
* toPlainText also returns str
* `QTreeWidgetItem.text` returns str
