Auto-Remediation - Show available solutions in Project Security Dashboard - Add filtering capability - Documentation

• Main issue: #258800 (closed)
• Parent issue: #258814 (closed)
• frontend counterpart: #258817 (closed)

Implementation plan

• Add information to https://docs.gitlab.com/ee/user/application_security/vulnerability_report/index.html about the new filtering capabilities.
• Add screenshot to https://docs.gitlab.com/ee/user/application_security/vulnerability_report/index.html that shows new functionality in Activity column (related MRs)