Multi window accessibility

[kryksyh]

this is a counter part of: musescore/MuseScore#32797

• I signed the CLA
• The title of the PR describes the problem it addresses
• Each commit's message describes its purpose and effects, and references the issue it resolves
• If changes are extensive, there is a sequence of easily reviewable commits
• The code in the PR follows the coding rules
• There are no unnecessary changes
• The code compiles and runs on my machine, preferably after each commit individually
• I created a unit test or vtest to verify the changes I made (if applicable)

Build configuration

audacity: audacity/audacity/master
audacity platforms: linux_x64
musescore: kryksyh/MuseScore/multi-window_accessibility
musescore platforms: linux_x64

[kryksyh]

/build