Improve UTF8 Tests for Invoke-WebRequest and Invoke-RestMethod #4890
Description
The current tests (soon to be) added in #4869 are an improvement from before but, perhaps, some better tests could be added.
Possibilities include ensuring there are no UTF16 or UTF32 chars, generating UTF8 from the WebListener controller instead of using a view, etc.
Also after #4888, a check can be made on the response headers from Invoke-RestMethod.