Fixes#129751
## Summary
Extends the EMS documentation to detail request and response headers the
browser sends to EMS resources and includes also a minimal `curl`
command to request the response headers for same resource as well.
I tried to edit this in a way it does not take the whole page but happy
to hear feedback or ideas on how to make this easier to digest.
27e83a5f-4d01-47a8-af2c-3739576bf56e
Also, I am not sure if this is something worth adding to our release
notes 🤔
