Add "filter" by tag config

@drugan I like the additional filter, but I also looked at https://github.com/swagger-api/swagger-ui/blob/master/docs/usage/configu... and added some more options in the patch I uploaded.

What do you think about adding more defaults than filters? And also about adding a configuration form so we can modify config via CLI or UI?

@afinnarn

I've tested your patch and all additions work great. Especially collapsing tags and adding a fragment of the currently expanded operation to the URL.

And yes, the configuration form would be useful. For example, there might be a case when you want to have a bird eye view on all the tags' operations expanded. If we go that way, obviously more defaults might be added so you can set up the UI exactly for your needs.

I was trying to add a form just now, but thinking more about it, the "openapi" module should probably include a section in "OpenApiListController" to hold the configuration link to fit with the current UI pattern. I got stuck on what the proper path should be and how to handle config forms within that.

For example, the path "/admin/config/services/openapi/swagger/my_json_api" shows the Swagger UI, but how would you add a setting form to that? "/admin/config/services/openapi/swagger/settings" isn't a good idea, and "/admin/config/services/openapi/settings/swagger" is also weird.

So, I won't try to add the form right now until I look more at the main openapi module. Any thoughts are welcome, but that will be my approach to furthering this ticket.