No Audible Announcement of When the Equation Editor Appears or Disappears When Editing a Document with a Screen Reader

# Description
A common question asked by non-visual users is how do I know when I am in the Equation Editor. When using either the NVDA or the JAWS screen readers, not audible indication is provided for when the Equation Editor appears nor when it disappears while arrowing through a document.

# Steps to Reproduce
1. Launch either the JAWS or NVDA screen readers configured to use MathCAT
2. Launch MS Word and create a new blank document
3. Type a short text phrase such as the sentence: `This is a random test. `
4. Press Alt+= to bring up the Equation Editor.
5. Type an expression such as `x=y`
6. Right arrow over until the Equation Editor is gone (use sighted assistance if necessary) as no indication is provided
7. Type a space or period and then another short text phrase such as: `Just a sentence after an expression.`
8. Move to the start of the document, and then navigate to the end of the first sentence.
9. Press right arrow repeatedly to move into and then out of the the math expression.
10. Observe that no audible notification is provided that the Equation Editor appeared or disappeared.

# Sample document and demo video of the issue
- [Video: No announcement of when the Equation Editor in Word Appears or Disappears when Editing the Document with a Screen Reader (3 minutes)](https://iu.mediaspace.kaltura.com/media/t/1_fg4i2iox)
- [NoVerbalAnnouncementThatEquationEditorAppears.docx](https://github.com/user-attachments/files/17048822/NoVerbalAnnouncementThatEquationEditorAppears.docx)

# Credits
Mary Stores contributed to the writeup of this issue.

No source file or test is named. First reproduce the behavior in Microsoft Word with NVDA or JAWS configured for MathCAT, then trace the Equation Editor transitions while arrowing through the document; done means audible announcements occur both when entering and leaving the equation editor.

Written by the indexing model from the issue text.