fix: prioritize processing validator claims

[gzalz]

Problem
There is an edge case where validators with 10_000 commission bps are not able to have their claims process due to arithmetic calculations performed in the Tip Router program when the reward router claim is processed first.

Solution

• Guarantee the processing of validator claims before reward router claims
• While unprocessed validator claims are non-empty, keep processing those claims
• Only when no remaining validator claims need to be processed, process non-validator claims

[ebatsell]

lgtm