gitlab-advanced-sast-cpp: add cpp to advanced sast cwe coverage

Problem to solve

The gitlab-advanced-sast-cpp analyzer has been released in beta (!205649 (merged)), with both CI/CD templates and documentation published.

However, the CWE coverage for C++ has not yet been updated on the Advanced SAST coverage page.


Proposal

Investigate the gitlab-advanced-sast-cpp ruleset and add C++ to the user-facing CWE coverage documentation page.

Edited by Hua Yan