Allow 9 kms signers to better match gas consumption

[0xalexbel]

• Today, only 1 Kms signer is active. Allow the developer to optionally set 9 Kms signers to get a more accurate gas consumption. Maybe only when gas report is enabled ?

[jatZama]

No, not only for gas report, because it really changes the behavior in some edge cases, for eg some tx could revert because of out of gas with 9 signatures to check and not revert with only 1.