refactor: Replace Rollup with Vite (#2656)

This is a high risk change: every byte the card ships is emitted by a
different bundler, minified by a different minifier, and every
stylesheet is compiled by a different sass. The intent is that the
card's behaviour is unchanged.

**Significant development win**: Build time drops from 24s to 1.1s 🎉 

Also adds a test suite ('dist') that runs against the built bundle.

.vscode/launch.json

@@ -7,7 +7,7 @@
       "name": "Launch Chrome against Home Assistant",
       "url": "http://localhost:8123",
       "webRoot": "${workspaceFolder}/dist",
-      "preLaunchTask": "Rollup",
+      "preLaunchTask": "Vite",
       "resolveSourceMapLocations": ["http://localhost:1000/**"]
     }
   ]

.vscode/tasks.json

@@ -2,7 +2,7 @@
   "version": "2.0.0",
   "tasks": [
     {
-      "label": "Rollup",
+      "label": "Vite",
       "type": "shell",
       "command": "yarn",
       "args": ["start"],
@@ -17,8 +17,8 @@
         ],
         "background": {
           "activeOnStart": true,
-          "beginsPattern": "^bundles",
-          "endsPattern": "^created"
+          "beginsPattern": "^build started",
+          "endsPattern": "^built in"
         }
       },
       "isBackground": true,