Add support for reporting row and column headers in contenteditable HTML elements.

[msftedad]

Steps to reproduce:

Repro Steps:

1. Open the URL: https://ckeditor.com/ckeditor-4/demo/
2. Turn on NVDA.
3. Turn on NVDA Focus mode.
4. Add a new table and add column headers for the table
5. Now using ctrl + alt + arrow keys to navigate from one cell to another
6. Verify whether NVDA is announcing column headers or not.

Code pen for minimal sample: https://codepen.io/testaccount01/pen/rNvxdwJ

Actual behavior (Speech Viewer):-

For 1st table: -
row 2
column 1
row 1 a
row 2
row 3
column 2
column 2 b
column 1
row 3
column 2

For 2nd Table (Speech Viewer) :-
column 2 H2
column 1 H1
row 2 R1
column 2
column 3
row 1 H3
row 2
row 3
column 2
row 1 H3

NVDA is not announcing row or column headers.
-->

Expected behavior:

NVDA should announce row or column headers when we navigate from one cell to another cell. When it is going to the new cell it should announce the column headers of the new cell.

NVDA logs, crash dumps and other attachments:

[2137516_NVDA is not announcing headers as headers in table in CKEditor demo (1).zip](https://microsoftapc-my.sharepoint.com/:u:/g/personal/v-deenthakur_microsoft_com/EaKv3yxacN1MmmAJ7Wui7DEBIrBRE87w_QnNbzrbUP3kGQ?e=AddeMk)

System configuration

NVDA installed/portable/running from source:

Installed

NVDA version:

NVDA Version 2022.2

Windows version:

Windows 11 Version 10.0.22000 Build 22000

Name and version of other software in use when reproducing the issue:

Microsoft Edge Version 105.0.1343.27 (Official build) (64-bit)

Other information about your system:

N/A

Other questions

N/A

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

No

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Yes

[feerrenrut]

This is a missing feature in NVDA and would be considered an important and valuable addition.

[Adriani90]

Note that for example Microsoft 365 Word online is basically built on such contentEditable structures, so solving thin in NVDA would also improve probably alot the experience in Word Online.

[michaelDCurran]

For anyone implementing this, take a look at the _getControlFieldForObject method on class CompoundTextInfo in compoundDocuments.py.
It should be a simple as filling in table-rowheadertext and table-columnheadertext attributes using values of obj.rowHeaderText and obj.columnHeaderText respectively.
Here is a very simple test_contenteditable_table.html.txt. Make sure to switch to focus mode, and use control+alt+arrow keys to move around the table.
It is expected that NvDA would report the appropriate day column header and time row header when moving between the cells in this calendar.