Lookup tab

[chucker]

Existing features:

• [x] Enter address

Um, this is a bit unclear. In Snow Leopard, this was clearly a dig front-end:

But in Catalina, the "select the information to lookup" drop-down is gone, and the output vastly simplified:

However, that's not the (default) output of host, dig, or dscacheutil, for that matter?

I feel like we should do these new features:

• [x] Let users choose between dscacheutil and dig and explain why (see below)
• [x] When choosing dig, bring back the drop-down to let users choose a particular record
• [x] For dig: -x (reverse lookup). Either in the above drop-down, or as a checkbox.

(•) macOS Directory Services (`dscacheutil`): matches Safari's behavior
( ) BIND (`dig`): matches Unix behavior, and offers more option

[chucker]

Not bad for entirely in XAML. (The NSTextField looks wrong, as does the font rendering. But whipping up that layout so quickly is cool. You might say it is… swift UI development without SwiftUI.)

[chucker]

Now if only we could figure out all the options in that drop-down…