Fix POSTing empty body in Work Package Form spec

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Correct Work Package API spec to use query strings

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Merge pull request #2351 from opf/fix/minor-api-v3-spec-issues

Fix various issues with API v3 request specs