[chassis][voq] fix for voq fabric related tests (#16068)

What is the motivation for this PR?
Fixing issue 16067.

How did you do it?
Changed to not re-write originalIsolateStatus but instead write to isolateStatus.
Also added try/catch block to both tests as today if the test fails it exits without restoring the state of the port.

I also added check to tests/voq/test_fabric_reach.py::test_fabric_reach_supervisor to run against only if asic is present. Right not the tests get the max asics for the platform and assumes they are all present.

How did you verify/test it?
Ran against t2 Nokia chassis