fix: rewards issue

[Divya-Solulab]

Proposed changes

This update addresses an edge case in transaction fee history calculations. The issue arises when there are only two rewards in the fee history. In such cases, calculating percentage increases would produce a single-element list, causing an error during unpacking.

Additionally, we’ve identified a potential edge case: if only one reward is present, calculating percentage increases would yield an empty list, leading to a failure.

Fixes

• Resolved unpacking issue by removing the unpack operator.
• To handle the single-reward scenario, we’ve introduced a fallback mechanism:
  • Incrementally adjust the fee history percentile up to a maximum of 3 retries to obtain at least two rewards.

[0xArdi]

The doc link fix is on #769