mcnc benchmarks in wrong place / missing in regtests

[vaughnbetz]

1. Right now there appears to be an mcnc test over a bunch of benchmarks that tests implementation and formal equivalence in the regression_mcnc in vtr_reg_basic, but it isn't in the task list so it isn't running.
   This test is probably too big and slow to be in basic anyway, but it shouldn't be in the directory then.

vtr_reg_strong has a smaller mcnc test (only a few circuits). It doesn't check equivalence.

The orphaned test in vtr_reg_basic should probably be moved to one of the vtr_nightly tests, and added to the task list.

2. vtr_reg_multiclock appears to not run in CI. It's above all the regression directories that are automatically run, and instead has a task list that refers to a non-existent vtr_reg_nightly_basic/ directory. Some of these tests may not be that important (testing multiclock flows that aren't the default), but the multiclock iterative is the default and should be tested. Can you also look into this one Arash? If the test all works it should simply be moved to one of the vtr_reg_nightly tests. If some parts don't work we can discuss to see what parts need to be kept.

[vaughnbetz]

@ArashAhmadian : let me know if this is something you can handle.

[ArashAhmadian]

@vaughnbetz Sure, I will look into this.

[ArashAhmadian]

Closing issue.