fix: return correct columns for claimable rewards result

[seanmcgary]

Description

GetClaimableRewardsForEarner was scanning the wrong columns into the result struct resulting in a 0 value getting returned. This fixes GetClaimableRewardsForEarner to select the expected columns (token and amount) for the returned struct type.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Tests and manual testing

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings