Support state overrides in eth_call

[gzliudan]

The state override set option allows you to change the state of a contract before executing the call. This means you can modify the values of variables stored in the contract, such as balances and approvals for that call without actually modifying the contract on the blockchain.
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In more technical terms, the state override set is an optional parameter that allows executing the call against a modified chain state. It is an address-to-state mapping, where each entry specifies some state to be overridden prior to executing the call. Each address maps to an object containing:

FIELD	TYPE	BYTES 2	DESCRIPTION
balance	Quantity	<32	Fake balance to set for the account before executing the call.
nonce	Quantity	<8	Fake nonce to set for the account before executing the call.
code	Binary	any	Fake EVM bytecode to inject into the account before executing the call.
state	Object	any	Fake key-value mapping to override all slots in the account storage before executing the call.
stateDiff	Object	any	Fake key-value mapping to override individual slots in the account storage before executing the call.

The state override set is the third parameter in eth_call. We only support the first and the second parameters now. It is a new feature to the xdc blockchain.

Reference:

• https://docs.alchemy.com/reference/eth-call
• https://docs.allthatnode.com/reference/eth_call

[liam-lai]

Report by EIP-4337 patch

[wgr523]

Code is in PR #529