Call yosys-config post build extraction for sanity check. Report absolute path for yosys exe if it can't be found.
Also updates `macro_commands.py` to skip empty lines, and moves comment stripping earlier in parsing.
Also adds `docs/tests/macro_commands.py` which checks all commands in `code_examples/macro_commands` against the current yosys build. Format similar to `run-test.sh` files: logging the file under test and reporting errors.