Add property page accessible role for settings tabs and name for document tabs

[LeonarddeR]

• Add a small accessibility module exposing AccProps/AccessibleExt for setting accessible name/role on any wxdragon widget
• Set ROLE_PROPERTYPAGE + the tab's title as accessible name on the three Options dialog tab panels, so screen readers announce them as pages on Ctrl+Tab
• Set the accessible name on each document tab's rich edit control to the document title. This ensures that switching between them with ctrl+tab announces the newly selected document properly.
  Note that this only works on Windows, I'm too unfamiliar with Mac to see what might need changing there.
  Also this slightly increases verbosity on the edit control because it mentions the title.

[trypsynth]

@LeonarddeR Thanks for this! Some thoughts:

Add a small accessibility module exposing AccProps/AccessibleExt for setting accessible name/role on any wxdragon widget

Can you please try upstreaming this into wxDragon instead? I did this for macOS after I confirmed my implementation of labeling combo boxes and it got accepted. Slightly more work, but worth it in the long run IMO

Also this slightly increases verbosity on the edit control because it mentions the title.

I'll have to try this out to see how much it annoys me, I might end up voting for making that configurable or finding a different way to do it, but time will tell on that one.
Thanks for this as usual!