fix (batcher): nonce verification order in handle_message function

[NicolasRampoldi]

Description

• The current implementation of the handle_message function in the batcher performs nonce verification using the check_nonce_and_increment method, which increments the nonce before pre-verifying the proof. This order of operations may introduce vulnerabilities, specifically to replay attacks and potential DoS.

[JuArce]

Solved in #1087