[Gateway] Enforce minimum stake when staking

[bryanchriswhite]

Summary

1. Adds minimum stake validation to the gateway stake message handler (i.e. total stake must be >= minimum stake).
2. Updates error returns in the same handler to ensure all error paths return appropriate gRPC status errors.
3. Replaces some warn and error level logs with info level, which I believe is more appropriate (until we have a practical debug level, at which point they should become debug logs).

Dependencies

• 809

Dependents

• 844

• 845

• 847

• 848

• 849

• 850

• 857

Issue

Gateway staking min stake validation.

• 612

Type of change

Select one or more from the following:

• [x] New feature, functionality or library
• [x] Consensus breaking; add the consensus-breaking label if so. See #791 for details
• [ ] Bug fix
• [ ] Code health or cleanup
• [ ] Documentation
• [ ] Other (specify)

Testing

• [ ] Documentation: make docusaurus_start; only needed if you make doc changes
• [x] Unit Tests: make go_develop_and_test
• [ ] LocalNet E2E Tests: make test_e2e
• [ ] DevNet E2E Tests: Add the devnet-test-e2e label to the PR.

Sanity Checklist

• [x] I have tested my changes using the available tooling
• [x] I have commented my code
• [x] I have performed a self-review of my own code; both comments & source code
• [ ] I create and reference any new tickets, if applicable
• [ ] I have left TODOs throughout the codebase, if applicable

[github-actions[bot]]

The CI will now also run the e2e tests on devnet, which increases the time it takes to complete all CI checks.

You may need to run make trigger_ci to submit an empty commit that'll trigger the tests.

GCP workloads (requires changing the namespace to 843)) Grafana network dashboard for devnet-issue-843