Add necessary class for success when calling EfsRpcEncryptFileSrv from PetitPotam

[coffeegist]

This PR fixes a current bug when using the PetitPotam module. Currently, when running PetitPotam via CME, if the call to EfsRpcOpenFileRaw has been patched, the following output is produced and a false negative is produced that the host is not vulnerable:

DEBUG [-] Connecting to ncacn_np:10.0.1.101[\PIPE\lsarpc]
DEBUG [+] Connected!
DEBUG [+] Binding to c681d488-d850-11d0-8c52-00c04fd90f7e
DEBUG [+] Successfully bound!
DEBUG [-] Sending EfsRpcOpenFileRaw!
DEBUG [-] Got RPC_ACCESS_DENIED!! EfsRpcOpenFileRaw is probably PATCHED!
DEBUG [+] OK! Using unpatched function!
DEBUG [-] Sending EfsRpcEncryptFileSrv!
DEBUG Something went wrong, check error status => 
    module 'payload_module' has no attribute 'EfsRpcEncryptFileSrvResponse'

This PR adds the necessary EfsRpcEncryptFileSrvResponse class to prevent the false negative.