Add draining transaction to reserve balance fail generator

[eclark0426]

No description provided.

[Copilot]

Pull Request Overview

This PR enhances the reserve balance fail generator by adding a draining transaction mechanism to handle cases where sender balance is too high. Instead of just logging a warning when the balance exceeds the threshold, the code now creates a draining transaction to reduce the balance to an appropriate level before generating the failing transactions.

Key changes:

• Replace warning-only behavior with active balance draining logic
• Simplify the transaction generation loop from iterator chain to explicit loop
• Remove unused itertools dependency

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