Feat/v6.3.1 support

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Summary

Adds compatibility with gTrade V6.3.1 contracts. Disclaimer: This version does not work for v6.3; Do not update your bot until v6.3.1 is released.

Changelog

• Adds second approval to Rewards contract (necessary to participate as same-blocks)
• Adds checks for LastUpdated to ensure trades that have recently been created or have updated SL/TP are only executed after the timeout has expired.