Feature Request: Read current overlay text using existing Dahua API

[TesLocker]

Problem
Not able to access the current overlay text for cameras.

Solution: Implement the "getConfig" API already enabled on Dahua Cameras
Dahua APIs already support a call to get the existing overlay text.

http://192.168.1.100/cgi-bin/configManager.cgi?action=getConfig&name=VideoWidget

Describe alternatives you've considered
Could use a helper variable and store the current text in the overlay, updating the helper each time the overlay text is updated. However, the overlay text can be changed outside of home assistant, as well.

Additional context