feat: support download of configs from Trivy cloud

[owenrumney]

Trivy cloud has endpoints that provide additional configs for secrets and misconfig scannning, when Trivy cloud integration is enabled, these configs should be downloaded when available.

The endpoints for configs are

GET /configs/secrets/{configName}

and

GET /configs/misconfig/{configName}

As with the ReportHook, this looks like it can be best achieved using the hooks mechanism and add a PreScan extension to download the configs if required and add them to scan setup.

[Utkarsh9571]

@owenrumney is this issue resolved?