test: MsgSetConsumerCommissionRate sets the rate correctly (backport #2110)

[mergify]

Description

Added an action in the E2E tests so that we can test that MsgSetConsumerCommissionRate sets the commission rate correctly. For simplicity, we introduce this test in the partial-set-security-opt-in E2E test and we do not test the exact rewards retrieved by each validator.

Tested locally with go run ./tests/e2e/... --tc partial-set-security-opt-in.

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Summary by CodeRabbit

• New Features

  • Introduced functionality to set and retrieve consumer commission rates for validators.
  • Added structured data types to manage parameters for setting consumer commission rates.
  • Enhanced state management to include consumer commission rates in chain state.

• Bug Fixes

  • Improved clarity in variable naming for the commission rate setting functionality.

• Tests

  • Added new test scenarios for managing consumer commission rates, ensuring the robustness of the testing framework.

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This is an automatic backport of pull request #2110 done by [Mergify](https://mergify.com).