Implement passthrough filtering in the ruleset package

Implementation Plan

1. Provide an API in https://gitlab.com/gitlab-org/security-products/analyzers/ruleset that checks which types of passthroughs are used in a custom configuration. This information can be used in https://gitlab.com/gitlab-org/security-products/analyzers/gitlab-advanced-sast to determine which passhthroughs should be applied and which passthroughs should be ignored.
2. For GLAS, we have to implement a filter that checks for the existence of taint rules if ruleset customization is used.
3. MR: Execute passthroughs selectively through Proces... (gitlab-org/security-products/analyzers/ruleset!62 - merged) • Julian Thome • 18.5