Repot all templates into a single directory (#3460)

The first step towards
https://github.com/paritytech/polkadot-sdk/issues/3155

Brings all templates under the following structure

```
templates
|   parachain
|   |   polkadot-launch
|   |   runtime              --> parachain-template-runtime
|   |   pallets              --> pallet-parachain-template
|   |   node                 --> parachain-template-node
|   minimal
|   |   runtime              --> minimal-template-runtime
|   |   pallets              --> pallet-minimal-template
|   |   node                 --> minimal-template-node
|   solochain
|   |   runtime              --> solochain-template-runtime
|   |   pallets              --> pallet-template (the naming is not consistent here)
|   |   node                 --> solochain-template-node
```

The only note-worthy changes in this PR are: 

- More `Cargo.toml` fields are forwarded to use the one from the
workspace.
- parachain template now has weights and benchmarks
- adds a shell pallet to the minimal template
- remove a few unused deps 


A list of possible follow-ups: 

- [ ] Unify READMEs, create a parent README for all
- [ ] remove references to `docs.substrate.io` in templates
- [ ] make all templates use `#[derive_impl]`
- [ ] update and unify all licenses
- [ ] Remove polkadot launch, use
https://github.com/paritytech/polkadot-sdk/blob/35349df993ea2e7c4769914ef5d199e787b23d4c/cumulus/zombienet/examples/small_network.toml
instead.

templates/parachain/node/src/rpc.rs

@@ -0,0 +1,56 @@
+//! A collection of node-specific RPC methods.
+//! Substrate provides the `sc-rpc` crate, which defines the core RPC layer
+//! used by Substrate nodes. This file extends those RPC definitions with
+//! capabilities that are specific to this project's runtime configuration.
+
+#![warn(missing_docs)]
+
+use std::sync::Arc;
+
+use parachain_template_runtime::{opaque::Block, AccountId, Balance, Nonce};
+
+pub use sc_rpc::DenyUnsafe;
+use sc_transaction_pool_api::TransactionPool;
+use sp_api::ProvideRuntimeApi;
+use sp_block_builder::BlockBuilder;
+use sp_blockchain::{Error as BlockChainError, HeaderBackend, HeaderMetadata};
+
+/// A type representing all RPC extensions.
+pub type RpcExtension = jsonrpsee::RpcModule<()>;
+
+/// Full client dependencies
+pub struct FullDeps<C, P> {
+	/// The client instance to use.
+	pub client: Arc<C>,
+	/// Transaction pool instance.
+	pub pool: Arc<P>,
+	/// Whether to deny unsafe calls
+	pub deny_unsafe: DenyUnsafe,
+}
+
+/// Instantiate all RPC extensions.
+pub fn create_full<C, P>(
+	deps: FullDeps<C, P>,
+) -> Result<RpcExtension, Box<dyn std::error::Error + Send + Sync>>
+where
+	C: ProvideRuntimeApi<Block>
+		+ HeaderBackend<Block>
+		+ HeaderMetadata<Block, Error = BlockChainError>
+		+ Send
+		+ Sync
+		+ 'static,
+	C::Api: pallet_transaction_payment_rpc::TransactionPaymentRuntimeApi<Block, Balance>,
+	C::Api: substrate_frame_rpc_system::AccountNonceApi<Block, AccountId, Nonce>,
+	C::Api: BlockBuilder<Block>,
+	P: TransactionPool + Sync + Send + 'static,
+{
+	use pallet_transaction_payment_rpc::{TransactionPayment, TransactionPaymentApiServer};
+	use substrate_frame_rpc_system::{System, SystemApiServer};
+
+	let mut module = RpcExtension::new(());
+	let FullDeps { client, pool, deny_unsafe } = deps;
+
+	module.merge(System::new(client.clone(), pool, deny_unsafe).into_rpc())?;
+	module.merge(TransactionPayment::new(client).into_rpc())?;
+	Ok(module)
+}