Minimum commission for validators (#10347)

* Minimum commission for validators

* rename

* Fix benchmakrs

* cargo run --quiet --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_staking --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/staking/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* Update frame/staking/src/pallet/mod.rs

* cargo run --quiet --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_staking --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/staking/src/weights.rs --template=./.maintain/frame-weight-template.hbs

Co-authored-by: Parity Bot <admin@parity.io>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/primitives/arithmetic/src/per_things.rs

@@ -833,6 +833,16 @@ macro_rules! implement_per_thing {
 			}
 		}
 
+		impl $crate::traits::Zero for $name {
+			fn zero() -> Self {
+				Self::zero()
+			}
+
+			fn is_zero(&self) -> bool {
+				self == &Self::zero()
+			}
+		}
+
 
 		#[cfg(test)]
 		mod $test_mod {