[InnerBrowser] Improved detection of content-type for .fail files (#5711)
[InnerBrowser] Improved detection of content-type for .fail files (#5711)

* Fix for file extension of .fail files.
The `Content-Type` header may contain a charset, which cause XML and JSON .fail files to have a .html extension.

* If a REST API outputs text/plain content, the .fail file should have the .txt extension.

Naktibalda/Codeception,Codeception/base,Codeception/base,Naktibalda/Codeception,Naktibalda/Codeception,Codeception/Codeception,Codeception/Codeception,Codeception/base