Option validation in Omniprobe

[rwvo]

One area for improvement (and reduces support requests) is error handling w.r.t. command line arguments, e.g.

• User made a typo in the path to the Triton cache: /.triton/cache instead of ~/.triton/cache. Instrumentation was happening, but instrumented kernels were never found. We may want to check if the provided directory is indeed a Triton cache directory.
• When writing output to file with -l /path/to/output.json, if the path does not exist, no output is written. We should either create the directory (if permissions allow), or catch and report the error early.

[rwvo]

May have been addressed already, but I'll ask copilot to check, and implement if it hasn't been.