fix: split claim rewards transactions

[alerodriargui]

General Changes

• Fixes the rewards claim flow so protocol rewards and Merit rewards are sent as separate wallet transactions instead of a single Multicall3 transaction.
• Avoids the UNPREDICTABLE_GAS_LIMIT / Multicall3: call failed error reported in issue 2745 when claiming both reward types together.
• Updates the transaction handler to support processing multiple main action transactions in sequence.

Developer Notes

Fixes #2745.
This change removes the combined multicall path for the claim-rewards flow so the wallet can estimate and submit each claim independently.

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Reviewer Checklist

Please ensure you, as the reviewer(s), have gone through this checklist to ensure that the code changes are ready to ship safely and to help mitigate any downstream issues that may occur.

• End-to-end tests are passing without any errors
• Code changes do not significantly increase the application bundle size
• If there are new 3rd-party packages, they do not introduce potential security threats
• If there are new environment variables being added, they have been added to the .env.example file as well as the pertinent .github/actions/* files
• There are no CI changes, or they have been approved by the DevOps and Engineering team(s)

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