Add basic regression framework

[sgherbst]

This will make it easier for us to validate pull requests like PR #1. You can look at DragonPHY as an example for how to set this up. The key things are to:

1. Set up a BuildKite pipeline for DaVE
2. Target a fault2 agent in .buildkite/pipeline.yml
3. If you want to run tests with fault using the ncsim simulator, my main tips are:
   1. Use the flags argument to pass the -sv flag. This is needed because some files in DaVE use SystemVerilog syntax but have a .v extension.
   2. Add these defines: {'DAVE_TIMEUNIT': '1fs', 'NCVLOG': None}. DAVE_TIMEUNIT could be set to any valid time unit like '1ps', '1ns', etc.
   3. Make sure that inc_dirs includes $mLINGUA_DIR/samples (may have to resolve that to an absolute path for fault)