[EPIC]: Create the independent go modules for `crypto` and `signer`

[mastereng12]

Context

crypto and signer modules are used in both cli and node, and go dependancies tree is very complicated in the main repo due to the L2 chain integrations. Separating the crypto and signer own modules will allow the cli repo deps more light.
Further more, decouple the L2 client integrations from the main repo to avoid the dep conflicts.

Tasks

• #531
• Create the own go module for signer

Further Steps

• #534
• #543

[mastereng12]

We will close it for now, created #543 to allow track it