[MLIR] Do not abort on invalid --mlir-debug-counter values (#181751)
Use `cl::Option::error()` diagnostics for invalid `--mlir-debug-counter`
arguments and exit with status 1 (no stack dump).
Added `mlir/test/mlir-opt/debugcounter-invalid-cl-options.mlir`
covering:
- non-numeric value (`-1n`)
- missing `=`
- missing `-skip`/`-count` suffix
Fixes #180117