Update "Enter a URL here to see what it currently matches" to also show linked parsers and api parsers

Finding which parser gets called by a URL can be difficult.

Typically I have to:

• Paste a URL into the Manage URL classes dialog, which displays the name of the matching URL class
• Find that URL class in the list and open it, to find the API URL, if any
• Possibly paste that URL into Manage URL classes to find its class
• Look at Manage URL Class links to find the parsers that are actually triggered.
• Go into parsers and find the relevant parser

Some of this is mitigated by using consistent names between the URL classes and parsers, but it's still a lot of jumping around.

Please add a feature to the Manage URL Classes "Enter a URL here" box that lets you directly open:

• Any related API URL classes
• Any parsers that will be triggered for that URL or it's API URLS

Sort of related to #801, but this is specifically for pasting a URL into the box and having Hydrus tell you which parsers and URL classes are related, and being able to open them directly from here.

Start in the Manage URL Classes dialog at the “Enter a URL here” workflow, then trace how it finds matching URL classes, API URL classes, and linked parsers. Done means the dialog exposes the related API URL classes and every parser triggered by the URL or its API URLs, with direct ways to open them.