[EVM] Random source with 32 bytes

[devbugging]

The get random source function on the Cadence arch now returns an uint64 (8 bytes), which is not ideal. We should return all the data we get from the random beacon which 32 bytes.

[turbolent]

Just curious: Why is it not ideal?

[devbugging]

@turbolent this is the thread where we discussed it: https://discord.com/channels/613813861610684416/1167476806333513800/1255560444425277481

[turbolent]

@sideninja Thank you!