fix(svm): make accs in create ata ix fn def not optional

[aspnxdd]

In the FunctionImplementation for GetAssociatedTokenAccount, the 2nd arg (args.get(2)) is required, but in the function definition it says it's optional. It is indeed not optional. Also the 3rd arg.

        let token_mint_address = SvmValue::to_pubkey(args.get(2).unwrap()).map_err(|e| {
            to_diag(fn_spec, format!("invalid token mint address for creating token account: {e}"))
        })?;

        let token_program_id = SvmValue::to_pubkey(args.get(3).unwrap()).map_err(|e| {
            to_diag(fn_spec, format!("invalid token program id for creating token account: {e}"))
        })?;

This PR changes the optional value in the function definition.

[MicaiahReid]

Good fine, thanks!