feat(debugger): debug Flutter apps through the Flutter debug adapter (#1474)

Dart projects that depend on the Flutter SDK were debugged through
`dart debug_adapter`, which cannot start a program importing dart:ui and has no
hot reload. A session now uses `flutter debug_adapter` when the program's or the
working directory's pubspec.yaml depends on the Flutter SDK, or when an attach
configuration asks for it (add-to-app: vm-service-uri and device map to the
adapter's attach arguments). Hot Reload and Hot Restart are sent over DAP and
appear in the toolbar of Dart sessions. Dart files also get a debug configuration.

Co-authored-by: payailk <[email protected]>

src/ui/icons.tsx

@@ -361,6 +361,7 @@ const ICONS = {
   "gutter-overriding": "gutter/overridingMethod",
   stop: "run/stop",
   rerun: "run/rerun",
+  "hot-reload": "openidea/general/hotReload",
   "rerun-filled": "run/rerun_stroke",
   "restart-debug": "run/restartDebug",
   "restart-debug-filled": "run/restartDebug_stroke",

src/ui/openidea/general/hotReload.svg

@@ -0,0 +1,4 @@
+<!-- OpenIDEA: hot reload (a lightning bolt) in the expui style. -->
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M9.5 1.5L3.5 9H7.5L6.5 14.5L12.5 7H8.5L9.5 1.5Z" stroke="#6C707E" stroke-linejoin="round"/>
+</svg>