Add Information and warning messages to test-output

[OsirisTerje]

Immediate test-output to the Output/Tests window can be achieved by using the TestContext Error and Progress properties. There is an issue in NUnit https://github.com/nunit/nunit/issues/2908 to add the properties Information and Warning to these.

The Error correctly output as an Error, but Progress also do output as Error, but should be as information, Adding Information , which should be output as Information, and Warning as warning.

Also see #95 and #301, this should be a fix - or workaround for - those issues, although not utterly without pain, it will be possible to get the output into the Output/Test window instead of into the Output/Debug window.

[OsirisTerje]

Since 3.13 Progress is no longer output as Error, but as Information.