Log warning when PROC_MACRO exclusion is used with Cargo Lockfile Detector

[zahidblackduck]

JIRA Ticket
IDETECT-4850

Description
This merge request contains change to log a clear warning message when PROC_MACRO is included in the configured dependency-type exclusions but will be ignored by the Cargo Lockfile Detector.

• Problem: --detect.cargo.dependency.types.excluded accepts NORMAL, BUILD, DEV, and PROC_MACRO. The Cargo Lockfile Detector cannot identify PROC_MACRO because those deps are not represented in Cargo.toml/Cargo.lock, so the exclusion will be ignored but was not clearly communicated.
• Change: Log a warning message when PROC_MACRO is present in the exclusion filter and the Cargo Lockfile Detector is running.
• Behavior: No functional change to detection flow. So, the execution continues, other valid exclusions are applied, and the process does not fail.