Fix bugs: (1) another infinite loop in e2e tests (2) missing validator info from genesis

[sergio-mena]

Contributes to #10

This PR contains the fix for two more bugs, one found in the implementation of vote extensions on our e2e app (testing code, not production), the other in the control routines of our e2e tests.

In order to share the troubleshooting process I followed (which someone might find useful), I will follow a similar approach to #539. I will push the commits, one by one, that roughly recreate the steps I followed to root-cause and fix the bugs. I also show I was first able to reproduce it, and then that the fix made the problem disappear. If you're interested, please check out the e2e test results of any steps (i.e., any commit pushed) by clicking on the little ❌ or ✅ next to the relevant commit.

• Commit#1: Fix infinite loop in e2e routines. We need this first so that, when we repro the other problem, the e2e tests fail (showing the logs, etc) rather than being cancelled by GitHub.
• Commit#2: Modify file ci.toml so that there are no updates at height 0 (representing the validator updates the app provides in ResponseInitChain) and that vote extensions are enabled before any other validator updates. Therefore, the app is obliged to use the genesis info it doesn't have (i.e. THE BUG) to verify vote extension signatures.
• Commit#3: the fix. We extend the functionality we introduced in Pass signatures of vote extensions in RequestPrepareProposal #489 which gathers validator data to also apply it with the info coming directly from genesis. There is a ❌ next to the corresponding commit hash, but it is due to the Golang linter failing; the e2e tests are passing for this commit.
• Commit#4: Fix golang lint.
• Commit#5: Revert commit#2, with the modifications done to expose the bug.

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PR checklist

• Tests written/updated
• Changelog entry added in .changelog (we use unclog to manage our changelog)
• Updated relevant documentation (docs/ or spec/) and code comments