shortcut mapper not accessible to screen readers.

Description of the Issue

This is a copy of issue #429 - reopening as requested. I was able to reproduce it with the latest Notepad++.

Steps to Reproduce the Issue

Open notepad++ with a screen reader such as nvda [nvaccess.org] and go to the settings menu with alt and arrow right to settings. 2. Activate the Shortcut mapper with nvda. 3. Press tab, and note that the list of keys isn't present, the only things present are close and one button called modify. 4. Press the insert key and numpad 7, (or if you are on a laptop keyboard, caps lock + page up) to activate screen review. If you are on a laptop, press insert+n (numpad insert or extended insert).Now go to preferences and keyboard settings > laptop layout, and also while there, check the use caps-lock as an nvda modifier key check box.Press okay. when I refer to the nvda key I mean (either one of caps-lock, insert, numpad insert. Press nvda+numpad 7 or in laptop mode, nvda+pg up. It should say screen review. 5. Now use either numpad 9 to go down by line, or nvda+down arrow to go down by line in laptop mode. If you do this correctly you should hear a number followed by an action. These keys should be put into a list (similar to what we have with the windows list so that a screen reader can properly work with them.

Expected Behavior

The table of shortcuts in the shortcut mapper dialog window should be accessible with a screenreader.

Actual Behavior

Screenreader doesn't recognize the table of shortcuts as a table, therefore it's impossible to interact with it, for example, it is impossible to change any shortcuts.

Debug Information

Notepad++ v7.7.1 (64-bit) Build time : Jun 16 2019 - 21:24:47 Path : c:\program files\notepad++\notepad++.exe Admin mode : OFF Local Conf mode : OFF OS : Windows 10 (64-bit) Plugins : DSpellCheck.dll mimeTools.dll NppConverter.dll NppGTags.dll

Please note, that I didn't try removing NppGTags plugin, as I am trying to set up shortcuts for that plugin, since it doesn't have any default shortcuts.