Updates the group security dashboard docs to include filters and dependency scanning

What does this MR do?

Updates the group security dashboard docs to include filters and dependency scanning

• Adds references to the dependency scanning features
• Updates the images to reflect the new layout
• Adds a small section about the new filters

Related issues

#6240 (closed) and #8481 (closed)

Author's checklist

• Apply the correct labels and milestone
• Crosslink the document from the higher-level index
• Crosslink the document from other subject-related docs
• Feature moving tiers? Make sure the change is also reflected in features.yml
• Correctly apply the product badges and tiers
• Port the MR to EE (or backport from CE): always recommended, required when the ee-compat-check job fails

Review checklist

• Your team's review (required)
• PM's review (recommended, but not a blocker)
• Technical writer's review (required)
• Merge the EE-MR first, CE-MR afterwards