[Feature] Add support for start and end heights returned by GetEventsForHeightRange

[justinbarry]

Following this issue.

After that, we need to decide how to support it going forward. Two options:

1. Surface the "end_height" to the dapp, allowing the dapp to decide on when to poll for the missing blocks.
2. FCL internally will keep polling until all the blocks are requested.

[spacepluk]

FWIW in our dapp if we don't get all the events for a range we're going to request the whole thing again.

[bluesign]

Surface the "end_height" to the dapp, allowing the dapp to decide on when to poll for the missing blocks.
FCL internally will keep polling until all the blocks are requested.

why not both?

[spacepluk]

I think 1 is a prerequisite for 2.

[justinbarry]

@spacepluk Depends on if we decide to build the "retry" login into FCL proper or not. Given that we prefer keeping FCL Core simple, we will probably choose option 1 with some nifty JS Doc examples showcasing retry logic. Retrying the whole range is a very viable option.

There is a conversation happening here around streaming events which will remove the need for polling.