Swap out primary UI color for Zoo brand blue, add theme color setting to control its hue (#2017)

* Add a setting for themeColor

* Add primary-color to Tailwind, driven by themeColor setting

* Get rid of most uses of "energy" colors

* Change out the rest of the energy colors

* Tweak NetworkHealthIndicator light mode checkmarks

* Handful of other CSS tweaks while I'm here:
- remove the AppHeader bg and border
- pane margins
- better dark mode button styles

* Make Zoo logomark a badge

* A snapshot a day keeps the bugs away! 📷🐛 (OS: ubuntu)

* Re-run CI post-snapshots

* A snapshot a day keeps the bugs away! 📷🐛 (OS: ubuntu)

* Retrigger CI

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/components/Loading.tsx

@@ -15,23 +15,20 @@ const Loading = ({ children }: React.PropsWithChildren) => {
       data-testid="loading"
     >
       <svg viewBox="0 0 10 10" className="w-8 h-8">
-        <circle cx="5" cy="5" r="4" stroke="var(--energy-50)" fill="none" />
         <circle
           cx="5"
           cy="5"
           r="4"
-          stroke="var(--energy-10)"
+          stroke="var(--primary)"
           fill="none"
           strokeDasharray="4, 4"
           className="animate-spin origin-center"
         />
       </svg>
-      <p className="text-base mt-4 text-energy-80 dark:text-energy-30">
-        {children || 'Loading'}
-      </p>
+      <p className="text-base mt-4 text-primary">{children || 'Loading'}</p>
       <p
         className={
-          'text-sm mt-4 text-energy-70 dark:text-energy-50 transition-opacity duration-500' +
+          'text-sm mt-4 text-primary/60 transition-opacity duration-500' +
           (hasLongLoadTime ? ' opacity-100' : ' opacity-0')
         }
       >