[Feat.Req] Check receipt timestamps early

[aasseman]

Problem statement
We are not checking (in indexer-service) that new receipts have a reasonably accurate timestamp (let's say within 5 seconds of our own clock). So as it is right now it is not really safe :/.

Expectation proposal
Check in-band that receipt timestamps are reasonably close to the system clock.

Additional context
#83 (comment)

[gusinacio]

Closed by #155