validation for bounded range for data time range

[pjain1]

In metrics time range resolver and other places we treat zero time as no data. When rill time like inf is used then returns start as zero time and that gets converted to nil values for all min/max timestamps so disallow such unbonded time ranges when defining static data time ranges.

I thought of changing the behaviour but if min is zero time that means 0001 year in golang, does that even mean anything? also MetricsViewTimeRange API converts zero time to nil and UI currently does not do queries if min time in nil. So we are already assuming at various places that zero time means no data.

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

[nishantmonu51]

👍 , LGTM