Backend checklist

• Add module for parsing rill time syntax in backend.
• Add ResolveTime to return start and end times based on minTime, maxTime and now for a metrics view.
• Replace usage of old duration parser.
• Map old format to new format
• Add API to resolve times for a list of rill-times.
• Add a lot more tests.

UI checklist

• Add a parser in UI.
• Check if we really need to replicate the parser in UI. We could make the resolve time API to return parsed object as well.
• Integrate the new API to get start and end in UI.
• Categorise the time ranges into latest periodToDate and previous
• Add conversion to human readable label.
• Add E2E tests around time.
• Docs for the new rill time syntax @medriscoll