EVM: replace blocks' information with real values

The block in the kernel and in the proxy contain too much mocked values, this needs to be fixed:

1. Add more "real" information in L2 blocks
   • gas used
   • size
2. Encode them in RLP (like we do for receipts and objects)
3. Create "real" block constants from these blocks, it uses again too much mocked values
4. Remove mocked values from the proxy