(Show Redirects added) gatget do not load all redirects at the begining

[hypknot]

In visma.com page we are using this plugin for our custom redirects.
The issue we have with this tool is that we have a lot of custom redirects and way too much suggestions in our environment (10 million+). in this case when we open dashboard the gatget loads for ages and it takes a lot of resources of our environment. Also when "Dashboard" is opened by multiple editors it makes our environment quite slow while everything is loading.

In this case we decided to upgrade this gatget with one extra button "Show redirects".

When you open "Dashboard" the gatget firstly not try to show all redirects, but shows an empty list. in this case environment don't have heavy work to do. and if the user wants to see all redirects he just simply clicks "Show redirects" checkbox and at this point gatget will show all redirects. All other functionality is not changed, everything else is working as it should work.

Pros of this feature:

1. Gatget don't load all redirects unless you chose it.
2. Reduce load of environment when you open "Dashboard".

Cons of this feature:

1. One extra checkbox near the search input.

[evest]

I understand the problem, and think this is a reasonable request. We have started a change that will put the redirects in a separate database table to make it a lot faster for large amounts of redirects. This should effectively render this PR unnecessary. However, I'm tempted to merge this in for now, since I don't know when the new version will be done.

You have removed the nuget.org reference, so it does not build :-) I'll fix that.

Btw. you should really remove some of the suggestions, you can safely delete from that table, like everything older than half a year or so depending on how much history you'd like.