joyboy : Test contract Balance (#199)
* test deposit and claim amount with gas or not + check gas amount panic
* change request test balance
* scarb fmt
* escrow balance check before and after
* scarb fmt
* rename all balances vars for recipient sender and joy
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Co-authored-by: Maciej Kamiński @ StarkWare
https://github.com/keep-starknet-strange/joyboy/commit/a05cec5841eb50eab3b207c5706da4ea5e1b2101