[REST2] extend resource – view tests to check the right process is selected

[dariok]

Currently, the tests just check that something is returend.

To make sure we didn’t introduce errors in other places (specifically, wdb:getXslFromWdbMetas), we need to check that the right process is selected for

• just default
• default with a type other than text/html
• a view other than default, e.g. "md"

For this, we need to provide additional XSLTs and processes in wdbmeta.
This means either a dedicated test collection or we could add that to the documentation’s wdbmeta
Or, we ship a tei-metadata.xsl generically?