[fix]: parsing fixed

[Mohiiit]

1. Fixed parsing as per the documentation here: https://docs.starknet.io/documentation/architecture_and_concepts/Network_Architecture/on-chain-data/
   main changes were:
2. Added a new function to decode the da_word extract_bits_v2
3. In the data we also have class declaration, the parser function was only returning Vec< ContractUpdate> but now it would be returning DataJson which is:

pub struct DataJson {
    pub state_update_size: u64,
    pub state_update: Vec<ContractUpdate>,
    pub class_declaration_size: u64,
    pub class_declaration: Vec<ClassDeclaration>,
}

[AbdelStark]

Lgtm