pallet benchmarking: Bump default steps and repeat (#14408)

* Bump default steps and repeats to useful values

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Add check that scheduler weight depends on component

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Add test to whitelist pallet

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Add env var to disable checks

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* remove tests

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Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>