VSCode: Prepare for pioarduino transition (#10471)

Start reccomending the pioarduino VS Code extension instead of the PlatformIO extension.

pioarduino-based builds cannot complete correctly using the platformio extension. Normal platformio builds (nrf52, stm32) are unaffected//still work correctly.

Devs may need to delete their ~.platformio and .pio directories once after install in order to build properly.

.vscode/extensions.json

@@ -1,10 +1,10 @@
 {
-    // See http://go.microsoft.com/fwlink/?LinkId=827846
-    // for the documentation about the extensions.json format
     "recommendations": [
-        "platformio.platformio-ide"
+        "Jason2866.esp-decoder",
+        "pioarduino.pioarduino-ide"
     ],
     "unwantedRecommendations": [
-        "ms-vscode.cpptools-extension-pack"
+        "ms-vscode.cpptools-extension-pack",
+        "platformio.platformio-ide"
     ]
 }