Support for auditing views

[RafaelAPB]

We now send assets across chains from gateway to gateway. Gateways communicate proofs which are blockchain views + metadata. Support the audit of these views, within a SATP plugin. Create endpoints within BUNGEE or SATP (that calls BUNGEE) to implement the following

Requirements:

1. Given a timeframe: collect all views generated in that timeframe.
2. For each view, check the proof. Verify the proof on chain.
3. Generate the audit report. It should include information about the view, the involved gateways, recipient and sender, etc, according to relevant regulations. These papers might be good starting points: https://d197for5662m48.cloudfront.net/documents/publicationstatus/182924/preprint_pdf/b2e391f7816989c0570fbf7caa5b06cb.pdf and https://d197for5662m48.cloudfront.net/documents/publicationstatus/170345/preprint_pdf/a21ca77abd647e378638d0ecd0a9c023.pdf
4. Export audit report to JSON/HTML
5. Expose endpoint to initiate audit
6. Update Prometheus metrics (number of audits conducted, number of states analysed, number of views analysed, etc)
7. Create simple UI that allows initiating an audit, and read the report

[eduv09]

@RafaelAPB please assign me this one

[RafaelAPB]

This is lower priority than #3111