[parachain-template] benchmarks into mod benchmarks (#3818)

This PR introduces a dedicated module for benchmarks within the
parachain runtime. By segregating benchmarks into their own module, we
achieve a cleaner project structure and improved readability,
facilitating easier maintenance and updates.

### Key Changes:
- **New Benchmarks Module**: A new file `benchmarks.rs` is added,
encapsulating the benchmarking code for various pallets.
- **Refactoring `lib.rs`**: The main runtime library file (`lib.rs`) has
been updated to reflect the extraction of benchmark definitions. By
moving these definitions to `benchmarks.rs`, we reduce clutter in
`lib.rs`, streamlining the runtime's core logic and configuration.

### Benefits of This Refactoring:
- **Focused Benchmarking**: Developers can now easily locate and modify
benchmarks without navigating through the core runtime logic, enabling
targeted performance improvements.
- **Cleaner Codebase**: Segregating benchmarks from the main runtime
logic helps maintain a clean, well-organized codebase, simplifying
navigation and maintenance.
- **Scalability**: As the parachain evolves, adding or updating
benchmarks becomes more straightforward, supporting scalability and
adaptability of the runtime.

### Summary of Changes:
- Created `benchmarks.rs` to house the benchmarking suite.
- Streamlined `lib.rs` by removing the inlined benchmark definitions and
linking to the new benchmarks module.

---------

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

templates/parachain/runtime/src/benchmarks.rs

@@ -0,0 +1,36 @@
+// This is free and unencumbered software released into the public domain.
+//
+// Anyone is free to copy, modify, publish, use, compile, sell, or
+// distribute this software, either in source code form or as a compiled
+// binary, for any purpose, commercial or non-commercial, and by any
+// means.
+//
+// In jurisdictions that recognize copyright laws, the author or authors
+// of this software dedicate any and all copyright interest in the
+// software to the public domain. We make this dedication for the benefit
+// of the public at large and to the detriment of our heirs and
+// successors. We intend this dedication to be an overt act of
+// relinquishment in perpetuity of all present and future rights to this
+// software under copyright law.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+// For more information, please refer to <http://unlicense.org>
+
+frame_benchmarking::define_benchmarks!(
+	[frame_system, SystemBench::<Runtime>]
+	[pallet_balances, Balances]
+	[pallet_session, SessionBench::<Runtime>]
+	[pallet_timestamp, Timestamp]
+	[pallet_message_queue, MessageQueue]
+	[pallet_sudo, Sudo]
+	[pallet_collator_selection, CollatorSelection]
+	[cumulus_pallet_parachain_system, ParachainSystem]
+	[cumulus_pallet_xcmp_queue, XcmpQueue]
+);

templates/parachain/runtime/src/lib.rs

@@ -255,22 +255,10 @@ construct_runtime!(
 	}
 );
 
-#[cfg(feature = "runtime-benchmarks")]
-mod benches {
-	frame_benchmarking::define_benchmarks!(
-		[frame_system, SystemBench::<Runtime>]
-		[pallet_balances, Balances]
-		[pallet_session, SessionBench::<Runtime>]
-		[pallet_timestamp, Timestamp]
-		[pallet_message_queue, MessageQueue]
-		[pallet_sudo, Sudo]
-		[pallet_collator_selection, CollatorSelection]
-		[cumulus_pallet_parachain_system, ParachainSystem]
-		[cumulus_pallet_xcmp_queue, XcmpQueue]
-	);
-}
-
 cumulus_pallet_parachain_system::register_validate_block! {
 	Runtime = Runtime,
 	BlockExecutor = cumulus_pallet_aura_ext::BlockExecutor::<Runtime, Executive>,
 }
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarks;