Andrew7234/epoch tracking

[Andrew7234]

The task:

Currently, we INSERT INTO oasis_3.epochs (id, start_height) VALUES (current_epoch, current_height) ON CONFLICT DO NOTHING to get the earliest height as epoch start; similar order-reliant trick for end_height. Basically, we want to do the following for each block instead: start[curr_epoch] = min(old_value, curr_height); end[curr_epoch-1] = min(old_value, curr_height-1)

This PR:

Note: I believe the prior epoch tracking logic was slightly incorrect. Our openapi spec states that the end_height is description: The (inclusive) height at which this epoch ended. Omitted if the epoch is still active.

However, the prior code set the db end_height as the exclusive upper bound. This PR will now set the `end_height to be the inclusive upper bound as described. Eg,

  id   | start_height | end_height
-------+--------------+------------
 13402 |      10 |  19
 13403 |      20 |  29

I'm not quite sure which is more idiomatic, comments are welcome.

Test plan: light testing ran locally with e2e_regression tests over 601 blocks. Further verification is needed once we are able to run multiple parallel consensus analyzers.

Todo: investigate if/how we use epoch end_height in the rest of the indexer logic.

[mitjat]

Thank you!

[mitjat]

Thank you!
Nit: The commit title is very outdated.