Add Preferences section to Cutter plugin

[ITAYC0HEN]

Is your feature request related to a problem? Please describe

Currently one must use the Console to change r2ghidra's configuration

[0x100056b6]> e?r2ghidra
    r2ghidra.cmt.cpp: C++ comment style
 r2ghidra.cmt.indent: Comment indent
     r2ghidra.indent: Indent increment
       r2ghidra.lang: Custom Sleigh ID to override auto-detection (e.g. x86:LE:32:default)
    r2ghidra.linelen: Max line length
   r2ghidra.nl.brace: Newline before opening '{'
    r2ghidra.nl.else: Newline before else
     r2ghidra.rawptr: Show unknown globals as raw addresses instead of variables
 r2ghidra.sleighhome: SLEIGHHOME
    r2ghidra.verbose: Show verbose warning messages while decompiling 

Describe the solution you'd like

Dynamically add a new section to Cutter's Preferences view when loading the plugin.

Make sure to save and remember user preferences changes.

Describe alternatives you've considered Having a dedicated settings menu in Windows->Plugins

[karliss]

This would require adding an appropriate API to Cutter plugin interface.

An alternative approach would be something like what's discussed in radareorg/cutter#1965 / radareorg/cutter#1837 . That would still provide user with somewhat discoverable UI and work with plugins out of the box.