Add proper test Custom values (#1147)

* add proper tests for custom values

* remove try operators

* use sustrate compat for import of hash

* add license and hex

* add script to artifacts.sh

* custom values with ids not in metadata can be accessed in static interface

* fmt and clippy

* access bytes of custom values directly, even if type id wrong

* final fixes

* removing substrate-compat flag from ui tests

* Update subxt/src/custom_values/custom_values_client.rs

Co-authored-by: James Wilson <james@jsdw.me>

* remove types access in type generator

* 2 extra lines

---------

Co-authored-by: James Wilson <james@jsdw.me>

testing/ui-tests/src/correct/custom_values.rs

@@ -0,0 +1,47 @@
+use codec::{Decode};
+use subxt::{config::substrate::H256, OfflineClient, PolkadotConfig};
+use subxt_metadata::Metadata;
+
+#[subxt::subxt(runtime_metadata_path = "../../../../artifacts/metadata_with_custom_values.scale", derive_for_all_types = "Eq, PartialEq")]
+pub mod node {}
+use node::runtime_types::generate_custom_metadata::Foo;
+
+fn main() {
+    let api = construct_offline_client();
+
+    let expected_foo = Foo {
+        a: 42,
+        b: "Have a great day!".into(),
+    };
+
+    // static query:
+    let foo_address = node::custom().foo();
+    let foo = api.custom_values().at(&foo_address).unwrap();
+    assert_eq!(foo, expected_foo);
+
+    // dynamic query:
+    let foo_value = api.custom_values().at("Foo").unwrap();
+    let foo: Foo = foo_value.as_type().unwrap();
+    assert_eq!(foo, expected_foo);
+
+    // static query for some custom value that has an invalid type id: (we can still access the bytes)
+    let custom_bytes = api.custom_values().bytes_at("InvalidTypeId").unwrap();
+    assert_eq!(vec![0,1,2,3], custom_bytes);
+}
+
+fn construct_offline_client() -> OfflineClient<PolkadotConfig> {
+    let genesis_hash = {
+        let h = "91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3";
+        let bytes = hex::decode(h).unwrap();
+        H256::from_slice(&bytes)
+    };
+    let runtime_version = subxt::backend::RuntimeVersion {
+        spec_version: 9370,
+        transaction_version: 20,
+    };
+    let metadata = {
+        let bytes = std::fs::read("../../../../artifacts/metadata_with_custom_values.scale").unwrap();
+        Metadata::decode(&mut &*bytes).unwrap()
+    };
+    OfflineClient::<PolkadotConfig>::new(genesis_hash, runtime_version, metadata)
+}