chore: jail validators with invalid balances

[maharifu]

Related Github tickets

• https://github.com/VolumeFi/paloma/issues/1037

Background

If validators have invalid (or missing) balances, we jail them. Alternatively we could leave them out of the relayer pool, but this makes it more visible when something has failed.

For this mechanism to work properly, we need https://github.com/palomachain/pigeon/pull/399 to be merged as well.

Testing completed

• [x] test coverage exists or has been added/updated
• [x] tested in a private testnet

Breaking changes

• [x] I have checked my code for breaking changes
• [x] If there are breaking changes, there is a supporting migration.