fix: Convert vendor/pezkuwi-subxt from submodule to regular directory

vendor/pezkuwi-subxt/subxt/examples/constants_dynamic.rs

@@ -0,0 +1,26 @@
+#![allow(missing_docs)]
+use subxt::dynamic::Value;
+use subxt::{OnlineClient, PolkadotConfig};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Create a client to use:
+    let api = OnlineClient::<PolkadotConfig>::new().await?;
+
+    // We can query a constant by providing a tuple of the pallet and constant name. The return type
+    // will be `Value` if we pass this query:
+    let constant_query = ("System", "BlockLength");
+    let _value = api.constants().at(&constant_query)?;
+
+    // Or we can use the library function to query a constant, which allows us to pass a generic type
+    // that Subxt will attempt to decode the constant into:
+    let constant_query = subxt::dynamic::constant::<Value>("System", "BlockLength");
+    let value = api.constants().at(&constant_query)?;
+
+    // Or we can obtain the bytes for the constant, using either form of query.
+    let bytes = api.constants().bytes_at(&constant_query)?;
+
+    println!("Constant bytes: {:?}", bytes);
+    println!("Constant value: {}", value);
+    Ok(())
+}