Remove codec::Encode and codec::Decode derives from generated APIs by default (#2008)

* Remove codec::Encode and codec::Decode from generated APIs by default

* clippy fixes

* clippy

* More fixes, and CompactAs only if Encode/Decode

* revert println in example

* fix lightclient test

* fix docs

* Fix another rust doc comment

* Fix failing storage test

* Remove now-unnecessary test

* clippy

* clippy

* Remove pointless clone

subxt/examples/storage_fetch.rs

@@ -13,7 +13,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // Build a storage query to access account information.
     let account = dev::alice().public_key().into();
-    let storage_query = polkadot::storage().system().account(&account);
+    let storage_query = polkadot::storage().system().account(account);
 
     // Use that query to `fetch` a result. This returns an `Option<_>`, which will be
     // `None` if no value exists at the given address. You can also use `fetch_default`