BLOCK_DATA update

[OlivierBBB]

Main point

We need to modify the BLOCK_DATA module to support for variable (higher) BLOCK_GAS_LIMIT.

Details

The BLOCK_DATA module should verify that the BLOCK_GAS_LIMIT H_l satisfy the following properties, for every block in the conflation:

H_l < H_l' + q
H_l > H_l' - q
H_l < 2_000_000_000
H_l ≥ 61_000_000

q := H_l' / 1024

In the above H_l' is the preceding BLOCK_GAS_LIMIT. The above thus requires b + 1 BLOCK_GAS_LIMIT's, starting with the latest BLOCK_GAS_LIMIT from the last conflation. There will be some call's to WCP and MOD.

[letypequividelespoubelles]

@OlivierBBB instead of calling MOD, we should call EUC, every inputs will be < 8 bytes long.