When getting information about multiple VNF instances with invalid
attribute selector or invalid attribute-based filtering parameters,
tacker return a response with HTTP Code 200 and all information
about VNF instances. However, according to the specification file,
the HTTP code 400 Bad Request shall be returned.
To fix this bug, this patch adds a new check for this api`s
parameters. If it contains unsupported parameters, the HTTP code
400 Bad Request will be returned.
Closes-Bug: #1938108
Change-Id: I3cca6d6fa664dd8f88791516042892369e4972a2