Use `compute_new_account_address()` in unit tests

[chfast]

In the state_transition test suite we often need the address of to be created account. For now we just compute this address on the side and add it as constant.

It make sense to use the function compute_new_account_address() from host.cpp. It should be additionally split into two functions: compute_create_address and compute_create2_address because the CREATE/CREATE2 context is well known in the test definition.