feat: OS CLI output part I - update severity headline +test

[florindumitrascu]

• [x] Follows CONTRIBUTING rules

What does this PR do?

Improve snyk-open-source CLI output as follows:

• Severity and Title should be the only content on the line, similar to the web/ide
• [Severity] should be the first, in front of the title, similar to web/ide
• Remove the word ‘severity’ and only keeping [Critical], [High], [Medium], [Low]
• Proper color usage (e.g. Green shouldn’t be used for section titles)

Where should the reviewer start?

src/lib/formatters/remediation-based-format-issues.ts

How should this be manually tested?

Run 'snyk test' command on a local project and compare output formatting with the attached screenshot

Any background context you want to provide?

What are the relevant tickets?

TUN-269

Screenshots

Additional questions