feat: Improve output for dockerfile instructions

[pecodez]

• Follows CONTRIBUTING rules

What does this PR do?

This PR allows for use of the installCommand, extracted from a RUN instruction in newer versions of the SDP, to provide a better output for dockerFile user instructions.

https://snyksec.atlassian.net/browse/CAP-280

[github-actions]

	Warnings
⚠️	Since the CLI is unifying on a standard and improved tooling, we're starting to migrate old-style imports and exports to ES6 ones. A file you've modified is using either module.exports or require(). If you can, please update them to ES6 import syntax and export syntax. Files found: src/lib/snyk-test/run-test.ts test/acceptance/cli-test/cli-test.docker.spec.ts

Generated by 🚫 dangerJS against 4690660

[agatakrajewska]

I think we actually could release the SDP first, and add that bump here, so we only raise the cli PR once

[ghost]

Looks good! I'd suggest find/replacing all usages of "instruction" in this context to "install command" in test names, variable names, etc. It's confusing/inconsistent otherwise.