Rename TRIVY_DEBUG to CS_DEBUG

Why are we doing this work

We want to avoid scanner-specific variables in our documentation.

As often as possible, we want to abstract the underlying scanner's variables under a CS_ name so that:

1. The same variable can work for any scanner in the container scanning analyzer
2. Users don't get the impression that it's safe to use any scanner-specific variables

As this is a breaking change, we want to do it in %14.0.

Relevant links

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

1. Rename TRIVY_DEBUG
   1. In gcs
   2. In the docs