feat(studio): real install progress in the store dialog and the wizard

Both surfaces showed an indeterminate spinner for the whole install,
because the hub only offered a unary call. They now follow
HubAdmin/InstallModuleStream:

- The store's install dialog shows the phase in plain language, the
  overall percentage, megabytes while the size is known, and a seconds
  counter. The counter is the second, independent signal: it keeps
  running even if the hub goes quiet, which is what tells 'slow' apart
  from 'stuck'.
- The setup wizard shows the same bar per module instead of a spinner
  inside the button.
- New strings in both locales for the phases, the byte line and the
  elapsed counter.

progress_bar_visual_test writes the four waiting states to
build/progress/ in either theme, so the result can be judged without
launching the desktop app. Writing it turned up a real trap worth
recording: awaiting toImage() directly in a widget test leaves the
binding waiting forever - the file passed in six seconds, then sat
there until the ten-minute timeout failed the whole suite.
tester.runAsync() is the fix. Full suite: 186 passed.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_de.arb

@@ -489,6 +489,12 @@
     }
   },
   "storeInstallProgressBody": "Holen, verifizieren, entpacken…",
+  "installPhaseResolve": "Modul wird gesucht",
+  "installPhaseDownload": "Wird heruntergeladen",
+  "installPhaseInstall": "Wird geprüft und entpackt",
+  "installPhaseDone": "Fertig",
+  "installBytes": "{done} von {total} MB",
+  "installElapsed": "{seconds} s vergangen",
   "storeLoadDocs": "Dokumentation laden",
   "storeDocsHint": "README inline gerendert; nutzt das Registry-Token des Hubs, falls nötig.",
   "storeDocsFetching": "README wird geladen…",

lib/l10n/app_en.arb

@@ -507,6 +507,29 @@
     }
   },
   "storeInstallProgressBody": "Fetching, verifying, unpacking…",
+  "installPhaseResolve": "Looking up the module",
+  "installPhaseDownload": "Downloading",
+  "installPhaseInstall": "Verifying and unpacking",
+  "installPhaseDone": "Done",
+  "installBytes": "{done} of {total} MB",
+  "@installBytes": {
+    "placeholders": {
+      "done": {
+        "type": "String"
+      },
+      "total": {
+        "type": "String"
+      }
+    }
+  },
+  "installElapsed": "{seconds} s elapsed",
+  "@installElapsed": {
+    "placeholders": {
+      "seconds": {
+        "type": "int"
+      }
+    }
+  },
   "storeLoadDocs": "Load documentation",
   "storeDocsHint": "README rendered inline; uses the hub's registry token when needed.",
   "storeDocsFetching": "Fetching README…",

lib/l10n/app_localizations.dart

@@ -1982,6 +1982,42 @@ abstract class AppLocalizations {
   /// **'Fetching, verifying, unpacking…'**
   String get storeInstallProgressBody;
 
+  /// No description provided for @installPhaseResolve.
+  ///
+  /// In en, this message translates to:
+  /// **'Looking up the module'**
+  String get installPhaseResolve;
+
+  /// No description provided for @installPhaseDownload.
+  ///
+  /// In en, this message translates to:
+  /// **'Downloading'**
+  String get installPhaseDownload;
+
+  /// No description provided for @installPhaseInstall.
+  ///
+  /// In en, this message translates to:
+  /// **'Verifying and unpacking'**
+  String get installPhaseInstall;
+
+  /// No description provided for @installPhaseDone.
+  ///
+  /// In en, this message translates to:
+  /// **'Done'**
+  String get installPhaseDone;
+
+  /// No description provided for @installBytes.
+  ///
+  /// In en, this message translates to:
+  /// **'{done} of {total} MB'**
+  String installBytes(String done, String total);
+
+  /// No description provided for @installElapsed.
+  ///
+  /// In en, this message translates to:
+  /// **'{seconds} s elapsed'**
+  String installElapsed(int seconds);
+
   /// No description provided for @storeLoadDocs.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -1089,6 +1089,28 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get storeInstallProgressBody => 'Holen, verifizieren, entpacken…';
 
+  @override
+  String get installPhaseResolve => 'Modul wird gesucht';
+
+  @override
+  String get installPhaseDownload => 'Wird heruntergeladen';
+
+  @override
+  String get installPhaseInstall => 'Wird geprüft und entpackt';
+
+  @override
+  String get installPhaseDone => 'Fertig';
+
+  @override
+  String installBytes(String done, String total) {
+    return '$done von $total MB';
+  }
+
+  @override
+  String installElapsed(int seconds) {
+    return '$seconds s vergangen';
+  }
+
   @override
   String get storeLoadDocs => 'Dokumentation laden';
 

lib/l10n/app_localizations_en.dart

@@ -1105,6 +1105,28 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get storeInstallProgressBody => 'Fetching, verifying, unpacking…';
 
+  @override
+  String get installPhaseResolve => 'Looking up the module';
+
+  @override
+  String get installPhaseDownload => 'Downloading';
+
+  @override
+  String get installPhaseInstall => 'Verifying and unpacking';
+
+  @override
+  String get installPhaseDone => 'Done';
+
+  @override
+  String installBytes(String done, String total) {
+    return '$done of $total MB';
+  }
+
+  @override
+  String installElapsed(int seconds) {
+    return '$seconds s elapsed';
+  }
+
   @override
   String get storeLoadDocs => 'Load documentation';