Migrate sdk archive table to Jaspr (#6312)

This migrates the sdk archives table shown in
https://dart.dev/get-dart/archive to
[Jaspr](https://github.com/schultek/jaspr).

There is no visual or functional change to the table from the end-user
perspective. Though I made some very light cosmetic changes:

- The `<form>` and `<table>` elements are now wrapped in an additional
`<div>` to act as the attach target for Jaspr.
- The template row changed from '0.0.0-0.0.dev (rev 00000) | Windows |
64-width | 01/01/1970 | JSON-formatted API documentation' to '0.0.0 (ref
00000) | --- | --- | 01/01/1970 | '.

I also added some new tests for the component using Jasprs testing
library.

---------

Co-authored-by: Parker Lougheed <parlough@gmail.com>

src/_sass/components/_misc.scss

@@ -122,6 +122,8 @@
 
 // Elements on the archive for each channel.
 #stable, #beta, #dev {
+  margin-top: 1rem;
+
   tbody {
     tr {
       transition: all .25s ease-in-out;