More Improvements to Benchmarking CLI + Generic WeightInfo (#7168)

* Generic WeightInfo, Output File Path

* Make `WeightInfo` generic

* Add support for header file

* fix line width

* add `--spaces` flag

* Configurable trait and struct strings

* make elections phragmen generic

* Add date to generated file

* Apply suggestions from code review

Co-authored-by: Gavin Wood <gavin@parity.io>

* fixes

* add settings metadata to output

Co-authored-by: nikvolf <nikvolf@gmail.com>
Co-authored-by: Gavin Wood <gavin@parity.io>

substrate/HEADER

@@ -0,0 +1,16 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.