chore: Expose missing GasFeeController methods through the messenger

[GuillaumeRx]

Explanation

This exposes missing methods used in the clients through the messenger after #8183

References

Progresses https://consensyssoftware.atlassian.net/browse/WPC-989

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Low risk: this only expands the messenger-exposed surface area and exported types, without changing gas estimation logic; main risk is downstream callers relying on the new action names/types.

Overview
Exposes two previously-unavailable GasFeeController methods via the messenger by adding GasFeeController:enableNonRPCGasFeeApis and GasFeeController:disableNonRPCGasFeeApis to the registered MESSENGER_EXPOSED_METHODS.

Adds new method action type definitions for these actions and re-exports them from src/index.ts, and documents the new messenger actions in the gas-fee-controller changelog.

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