XVM: payable calls from Wasm to EVM

[PierreOssun]

When executing an XVM payable call from Wasm to EVM, the AccountId of the contract hold some balance but it's H160 mapping address do not (it do not exist), resulting in the call to fail.
That why there is this line in test.

Suggestion:Check in XVM CE that if value is >0 the contract should have his H160 unified (if not unify it). The first payable XVM call will slightly have more weight than the following ones

[ashutoshvarma]

Even with AU enabled for user, wasm smart contract has no way to get his/her mapped evm address, that makes it impossible to approve/transfer assets on his behalf using XVM since we don't know what his/her evm address will be in order to construct the XVM call to ERC20 evm contract
Solution: Add a getter method in XVM CE & Precompile to fetch the mapped address from AU respectively.

[ashutoshvarma]

@PierreOssun this is fixed right and can be closed?