feat(policies): include code excerpt in policy breach display

[elsapet]

Description

Aim

• Add code extract with parent source and minimal highlighting to policy breach display
• Add full file path to policy breach display

To achieve the aim, I made some changes elsewhere in code:

• Add Target (i.e. the path the user asks us to scan) to settings.Config
• Separate schema decoding from classification decoding

Results:

Default setting

Checklist

• I've added test coverage that shows my fix or feature works as expected.
• I've updated or added documentation if required.
• I've included usage information in the description if CLI behavior was updated or added.
• PR title follows Conventional Commits format

[swarmia]

✅  Linked to AMA-3245 · Include code excerpt in policy breach display
➡️  Part of AMA-3235 · Table format for policies
➡️  Part of AMA-2947 · OSS - Curio CLI

[elsapet]

@cfabianski could you review when you have a moment? 🙏