Benchmark Offences Pallet (#5411)

* Add initial report_ofence bench.

* Remove unused imports

* Style nit

* Add nominators

* Remove logs.

* Nits.

* Add nominators param.

* Reorg, comment.

* Remove whitespaces.

* Apply review suggestion: move benchmark to own crate.

* Remove import.

* Remove line.

* Add feature flag.

* Pass can_report.

* Cleaning up.

* More cleaning

substrate/frame/offences/Cargo.toml

@@ -34,6 +34,7 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 ]
+runtime-benchmarks = []
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]