Function derive_metadata 

pub fn derive_metadata(
    mint: &Pubkey,
    payer: &Pubkey,
    nonce: u32,
    pid: &Pubkey,
) -> (Pubkey, u8)

Derive metadata PDA address for create_v2 instructions.

Seeds: ["strm-met", mint, payer, nonce_be_bytes]

For create_v2, payer is the sender. For create_unchecked_with_payer_v2, payer is the payer account.