[ScreenRuler] announce measurements when they are made

[yuyoyuppe]

Wasn't sure if this is already implemented: but should we have Narrator announce something when a measurement is made? Maybe not required for V1 though! Accesibility :)

Originally posted by @niels9001 in #19701 (review)

could be helpful: https://docs.microsoft.com/en-us/accessibility-tools-docs/items/win32/control_name