handle multiple upgrades for the same height in chain provider

[mkaczanowski]

TL;DR

Onchain governance allows a user to register multiple software upgrade proposals for the same height.
Blazar however needs to find the upgrade that will get executed, or is most likely to be executed at given height.

The selection process is quite simple (if there are more than one upgrade proposal per height):

1. if upgrade PASSED, use it
2. if there are multiple PASSED (unlikely), use the one with higher proposal ID
3. if no upgrade PASSED use the one with higher proposal ID (likely, a user wanted to "override" the older one)