Define and expose a results API interface for programmatic usage

[sgb-io]

Currently, results are returned in 2 forms:

• The CLI stdout, as a fixed summary message
• The full tree of FullyAnalyzedEntitys

Although the full tree can be used programmatically, it could be helpful to add a public API interface around this, so users can easily access some of the headlines from the output.

[sgb-io]

Relates to #38

[sgb-io]

Affects #39 - need this API added in order to easily get e.g. average complexity, most complex scores from a result

This API could also include a generateBadge() method that creates a badge .svg locally to the analyzed project, as per this suggestion

Actions to take

• Design a new results interface that is in turn exposed by codehawk-cli. It could be used via CLI or programmatically. We want: access to summary information about the results (such as average complexity score (+median?), worst complexity score), generateBadge()
• Consider providing new CLI options/commands to trigger actions that aren't the main processing (e.g. generate badge), this avoids the consuming project needing to script the same thing
• Investigate a OpenMetrics reporter so that users can track complexity over time