[FRAME] Warn on unchecked weight witness (#1818)

Adds a warning to FRAME pallets when a function argument that starts
with `_` is used in the weight formula.
This is in most cases an error since the weight witness needs to be
checked.

Example:

```rust
#[pallet::call_index(0)]
#[pallet::weight(T::SystemWeightInfo::remark(_remark.len() as u32))]
pub fn remark(_origin: OriginFor<T>, _remark: Vec<u8>) -> DispatchResultWithPostInfo {
	Ok(().into())
}
```

Produces this warning:

```pre
warning: use of deprecated constant `pallet::warnings::UncheckedWeightWitness_0::_w`: 
                 It is deprecated to not check weight witness data.
                 Please instead ensure that all witness data for weight calculation is checked before usage.
         
                 For more info see:
                     <https://github.com/paritytech/polkadot-sdk/pull/1818>
   --> substrate/frame/system/src/lib.rs:424:40
    |
424 |         pub fn remark(_origin: OriginFor<T>, _remark: Vec<u8>) -> DispatchResultWithPostInfo {
    |                                              ^^^^^^^
    |
    = note: `#[warn(deprecated)]` on by default
```

Can be suppressed like this, since in this case it is legit:

```rust
#[pallet::call_index(0)]
#[pallet::weight(T::SystemWeightInfo::remark(remark.len() as u32))]
pub fn remark(_origin: OriginFor<T>, remark: Vec<u8>) -> DispatchResultWithPostInfo {
	let _ = remark; // We dont need to check the weight witness.
	Ok(().into())
}
```

Changes:
- Add warning on uncheded weight witness
- Respect `subkeys` limit in `System::kill_prefix`
- Fix HRMP pallet and other warnings
- Update`proc_macro_warning` dependency
- Delete random folder `substrate/src/src` 🙈 
- Adding Prdoc

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

polkadot/runtime/parachains/src/hrmp.rs

@@ -554,14 +554,26 @@ pub mod pallet {
 		///
 		/// Origin must be the `ChannelManager`.
 		#[pallet::call_index(3)]
-		#[pallet::weight(<T as Config>::WeightInfo::force_clean_hrmp(*_inbound, *_outbound))]
+		#[pallet::weight(<T as Config>::WeightInfo::force_clean_hrmp(*num_inbound, *num_outbound))]
 		pub fn force_clean_hrmp(
 			origin: OriginFor<T>,
 			para: ParaId,
-			_inbound: u32,
-			_outbound: u32,
+			num_inbound: u32,
+			num_outbound: u32,
 		) -> DispatchResult {
 			T::ChannelManager::ensure_origin(origin)?;
+
+			ensure!(
+				HrmpIngressChannelsIndex::<T>::decode_len(para).unwrap_or_default() <=
+					num_inbound as usize,
+				Error::<T>::WrongWitness
+			);
+			ensure!(
+				HrmpEgressChannelsIndex::<T>::decode_len(para).unwrap_or_default() <=
+					num_outbound as usize,
+				Error::<T>::WrongWitness
+			);
+
 			Self::clean_hrmp_after_outgoing(&para);
 			Ok(())
 		}
@@ -575,9 +587,16 @@ pub mod pallet {
 		///
 		/// Origin must be the `ChannelManager`.
 		#[pallet::call_index(4)]
-		#[pallet::weight(<T as Config>::WeightInfo::force_process_hrmp_open(*_channels))]
-		pub fn force_process_hrmp_open(origin: OriginFor<T>, _channels: u32) -> DispatchResult {
+		#[pallet::weight(<T as Config>::WeightInfo::force_process_hrmp_open(*channels))]
+		pub fn force_process_hrmp_open(origin: OriginFor<T>, channels: u32) -> DispatchResult {
 			T::ChannelManager::ensure_origin(origin)?;
+
+			ensure!(
+				HrmpOpenChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32 <=
+					channels,
+				Error::<T>::WrongWitness
+			);
+
 			let host_config = configuration::Pallet::<T>::config();
 			Self::process_hrmp_open_channel_requests(&host_config);
 			Ok(())
@@ -592,9 +611,16 @@ pub mod pallet {
 		///
 		/// Origin must be the `ChannelManager`.
 		#[pallet::call_index(5)]
-		#[pallet::weight(<T as Config>::WeightInfo::force_process_hrmp_close(*_channels))]
-		pub fn force_process_hrmp_close(origin: OriginFor<T>, _channels: u32) -> DispatchResult {
+		#[pallet::weight(<T as Config>::WeightInfo::force_process_hrmp_close(*channels))]
+		pub fn force_process_hrmp_close(origin: OriginFor<T>, channels: u32) -> DispatchResult {
 			T::ChannelManager::ensure_origin(origin)?;
+
+			ensure!(
+				HrmpCloseChannelRequestsList::<T>::decode_len().unwrap_or_default() as u32 <=
+					channels,
+				Error::<T>::WrongWitness
+			);
+
 			Self::process_hrmp_close_channel_requests();
 			Ok(())
 		}