vProperty: check jCal roundtrip of positional parameters (pytest) #1553

vProperty types convert to jCal. Some of them contain more than one positional argument. #1526 addresses some of these where the parameters get lost.

To solve this issue:

• find the place in the tests where we list all property types. Use or create the fixture for parametrization.
• get one example of each property type and set parameters
• convert to jCal and back, assert that all parameters are still there.

See:

• Originally posted by @niccokunzmann in Preserve URI parameters on jCal round-trip #1526 (comment)
• icalendar.prop