Remove `Felt` serde

[Mirko-von-Leipzig]

Follow-up issue from #881.

We should aim at removing serde capabilities from Felt and its newtype wrappers in pathfinder_common. Serde specifics should be handled by each component directly. This lets us decouple components more correctly.

• [ ] investigate storage solution
  • mostly solved with ToSql and FromSql however these should move to storage from common
• [ ] investigate gateway solution
• [ ] investigate p2p solution
  • unclear if its not already good as is

[Mirko-von-Leipzig]

I think for json serde (rpc & gateway) we should consider a proc macro. Things we want to achieve:

1. Hex (with and without 0x prefix) and bigint decimal string serde, often for the same base type, but differently for rpc and gateway serde.
2. Use the original type - not crate specific types in the API
3. Minimal manual typing

I'm thinking we should be able to do annotations like:

    #[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
    #[serde(deny_unknown_fields)]
    pub struct L1ToL2Message {
        #[pf_serde("Hex")]
        pub from_address: EthereumAddress,
        #[pf_serde("Vec<Decimal>")]
        pub payload: Vec<L1ToL2MessagePayloadElem>,
        #[pf_serde("Hex")]
        pub selector: EntryPoint,
        #[pf_serde("Hex")]
        pub to_address: ContractAddress,
        #[serde(default)]
        #[pf_serde("Option<Hex>")]
        pub nonce: Option<L1ToL2MessageNonce>,
    }