feat: add merkl yield claim transaction type to TransactionType enum

[PatrykLucka]

Explanation

Adds a new merklYieldClaim transaction type to the TransactionType enum in the transaction controller. This enables the controller to properly categorize and handle transactions that claim yield rewards from Merkl Yield contracts (mUSD claim bonus). Without this type, Merkl yield claim transactions would fall under a generic category, making it harder to track and display them appropriately in the UI.

References

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

Adds a new transaction categorization for Merkl yield claims.

• Extend TransactionType enum with merklYieldClaim in types.ts
• Update CHANGELOG.md under Unreleased to record the new type

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[matthewwalsh0]

Temporary hold while we discuss use case.

[Matt561]

@PatrykLucka @matthewwalsh0 - Would a more generic "yieldClaim" tx type make more sense here? My understanding here is that we'd like the custom tx type to easily display yield claims in the activity list + potentially having custom confirmation screens down the road. @PatrykLucka Please correct me if I'm wrong! 😄