Initial In Instructions pallet and Serai client lib (#233)

* Initial work on an In Inherents pallet

* Add an event for when a batch is executed

* Add a dummy provider for InInstructions

* Add in-instructions to the node

* Add the Serai runtime API to the processor

* Move processor tests around

* Build a subxt Client around Serai

* Successfully get Batch events from Serai

Renamed processor/substrate to processor/serai.

* Much more robust InInstruction pallet

* Implement the workaround from https://github.com/paritytech/subxt/issues/602

* Initial prototype of processor generated InInstructions

* Correct PendingCoins data flow for InInstructions

* Minor lint to in-instructions

* Remove the global Serai connection for a partial re-impl

* Correct ID handling of the processor test

* Workaround the delay in the subscription

* Make an unwrap an if let Some, remove old comments

* Lint the processor toml

* Rebase and update

* Move substrate/in-instructions to substrate/in-instructions/pallet

* Start an in-instructions primitives lib

* Properly update processor to subxt 0.24

Also corrects failures from the rebase.

* in-instructions cargo update

* Implement IsFatalError

* is_inherent -> true

* Rename in-instructions crates and misc cleanup

* Update documentation

* cargo update

* Misc update fixes

* Replace height with block_number

* Update processor src to latest subxt

* Correct pipeline for InInstructions testing

* Remove runtime::AccountId for serai_primitives::NativeAddress

* Rewrite the in-instructions pallet

Complete with respect to the currently written docs.

Drops the custom serializer for just using SCALE.

Makes slight tweaks as relevant.

* Move instructions' InherentDataProvider to a client crate

* Correct doc gen

* Add serde to in-instructions-primitives

* Add in-instructions-primitives to pallet

* Heights -> BlockNumbers

* Get batch pub test loop working

* Update in instructions pallet terminology

Removes the ambiguous Coin for Update.

Removes pending/artificial latency for furture client work.

Also moves to using serai_primitives::Coin.

* Add a BlockNumber primitive

* Belated cargo fmt

* Further document why DifferentBatch isn't fatal

* Correct processor sleeps

* Remove metadata at compile time, add test framework for Serai nodes

* Remove manual RPC client

* Simplify update test

* Improve re-exporting behavior of serai-runtime

It now re-exports all pallets underneath it.

* Add a function to get storage values to the Serai RPC

* Update substrate/ to latest substrate

* Create a dedicated crate for the Serai RPC

* Remove unused dependencies in substrate/

* Remove unused dependencies in coins/

Out of scope for this branch, just minor and path of least resistance.

* Use substrate/serai/client for the Serai RPC lib

It's a bit out of place, since these client folders are intended for the node to
access pallets and so on. This is for end-users to access Serai as a whole.

In that sense, it made more sense as a top level folder, yet that also felt
out of place.

* Move InInstructions test to serai-client for now

* Final cleanup

* Update deny.toml

* Cargo.lock update from merging develop

* Update nightly

Attempt to work around the current CI failure, which is a Rust ICE.

We previously didn't upgrade due to clippy 10134, yet that's been reverted.

* clippy

* clippy

* fmt

* NativeAddress -> SeraiAddress

* Sec fix on non-provided updates and doc fixes

* Add Serai as a Coin

Necessary in order to swap to Serai.

* Add a BlockHash type, used for batch IDs

* Remove origin from InInstruction

Makes InInstructionTarget. Adds RefundableInInstruction with origin.

* Document storage items in in-instructions

* Rename serai/client/tests/serai.rs to updates.rs

It only tested publishing updates and their successful acceptance.

substrate/in-instructions/client/src/lib.rs

@@ -0,0 +1,47 @@
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
+use scale::Decode;
+
+use jsonrpsee_core::client::ClientT;
+use jsonrpsee_http_client::HttpClientBuilder;
+
+use sp_inherents::{Error, InherentData, InherentIdentifier};
+
+use in_instructions_pallet::{INHERENT_IDENTIFIER, Updates, InherentError};
+
+pub struct InherentDataProvider;
+impl InherentDataProvider {
+  #[allow(clippy::new_without_default)] // This isn't planned to forever have empty arguments
+  pub fn new() -> InherentDataProvider {
+    InherentDataProvider
+  }
+}
+
+#[async_trait::async_trait]
+impl sp_inherents::InherentDataProvider for InherentDataProvider {
+  async fn provide_inherent_data(&self, inherent_data: &mut InherentData) -> Result<(), Error> {
+    let updates: Updates = (|| async {
+      let client = HttpClientBuilder::default().build("http://127.0.0.1:5134")?;
+      client.request("processor_coinUpdates", Vec::<u8>::new()).await
+    })()
+    .await
+    .map_err(|e| {
+      Error::Application(Box::from(format!("couldn't communicate with processor: {e}")))
+    })?;
+    inherent_data.put_data(INHERENT_IDENTIFIER, &updates)?;
+    Ok(())
+  }
+
+  async fn try_handle_error(
+    &self,
+    identifier: &InherentIdentifier,
+    mut error: &[u8],
+  ) -> Option<Result<(), Error>> {
+    if *identifier != INHERENT_IDENTIFIER {
+      return None;
+    }
+
+    Some(Err(Error::Application(Box::from(<InherentError as Decode>::decode(&mut error).ok()?))))
+  }
+}