Ensure existing DS settings continue to work

Why are we doing this work

As decided in Spike: Audit DS analyzer options that impact do... (#475275 - closed), some settings that currently work in Gemnasium must continue to work in the new analyzer.

The settings are:

• DS_EXCLUDED_PATHS
• DS_MAX_DEPTH (already honored)
• DS_INCLUDE_DEV_DEPENDENCIES (already honored)
• SECURE_ANALYZERS_PREFIX (rather a CI template/component setting)

Relevant links

Relates to Add Dependency Scanning migration guide (!175029 - merged)

Verification steps

Verify the following settings work as defined:

• DS_EXCLUDED_PATHS - see #476224 (comment 2251142686)
• DS_MAX_DEPTH - see #476224 (comment 2251142686)
• DS_INCLUDE_DEV_DEPENDENCIES - see #476224 (comment 2251142686)
• SECURE_ANALYZERS_PREFIX - customers can use it in the analyzer_image_repository input - see #476224 (comment 2251777025)