Add show review from terminal options to settings.json

[7h3Rabbit]

Today when running webperf-core you can specify to show review(s) in terminal by using -r or --review for current run.

In this PR we make it possible to specify it in settings.json and have it persistent between runs:

{
    "general": {
        "review": {
            "show": true
        }
}

You can also use the longer form for use during current run:
python default.py --setting general.review.show=true -i sites.json

you should see this as the first steps of moving more and more options into settings.json.