Add support for aria-brailleroledescription from ARIA 1.3. (#14748)

partial fix for #11829

Summary of the issue:
ARIA 1.3 adds a aria-brailleroledescription attribute, which allows the web author to specify a string representation for an element's role, specific to Braille.
For example:

<button aria-roledescription="planet" aria-brailleroledescription="plnt">Saturn</button>
A button whos spoken role description will be "planet" but in Braille it will be shown as the abreviated "plnt".

Description of user facing changes
NVDA will honor the aria-brailleroledescription attribute if set by the web author, when presenting web content on a braille display.

Description of development approach
The internal work to support custom braille role text had already been added to NVDAObjects and controlFields to allow for Braille abbreviations for landmarks. this PR:

Implements roleTextBraille on the IA2Web NVDAObject, exposing the content of the brailleroledescription IAccessible2 attribute if available
In the Gecko ia2 virtualBuffer, normalizes the brailleroledescription IAccessible2 attribute to the roleTextBraille NvDA attribute on controlFields.

source/NVDAObjects/IAccessible/ia2Web.py

@@ -194,6 +194,12 @@ def _get_roleText(self):
 			return roleText
 		return super().roleText
 
+	def _get_roleTextBraille(self) -> str:
+		roleTextBraille = self.IA2Attributes.get('brailleroledescription')
+		if roleTextBraille:
+			return roleTextBraille
+		return super().roleTextBraille
+
 	def _get_states(self):
 		states=super(Ia2Web,self).states
 		# Ensure that ARIA gridcells always get the focusable state, even if the Browser fails to provide it.

source/virtualBuffers/gecko_ia2.py

@@ -140,6 +140,9 @@ def _normalizeControlField(self, attrs):  # noqa: C901
 		roleText=attrs.get("IAccessible2::attribute_roledescription")
 		if roleText:
 			attrs['roleText']=roleText
+		roleTextBraille = attrs.get("IAccessible2::attribute_brailleroledescription")
+		if roleTextBraille:
+			attrs['roleTextBraille'] = roleTextBraille
 		if attrs.get("IAccessible2::attribute_dropeffect", "none") != "none":
 			states.add(controlTypes.State.DROPTARGET)
 		if role==controlTypes.Role.LINK and controlTypes.State.LINKED not in states:

user_docs/en/changes.t2t

@@ -13,6 +13,7 @@ What's New in NVDA
   -
 - In Mozilla Firefox and Google Chrome, NVDA now reports when a control opens a dialog, grid, list or tree if the author has specified this using aria-haspopup. (#14709)
 - It is now possible to use system variables (such as ``%temp%`` or ``%homepath%``) in the path specification while creating portable copies of NVDA. (#14680)
+- Added support for the ``aria-brailleroledescription`` ARIA 1.3 attribute, allowing web authors to override the type of an element shown on the Braille display. (#14748)
 -