Token auth (#434)

* Embed device platform information into token request

* Remove username and password from userProfile

* Display icon to show if profile has associated user token

* Remove username / password from login settings screen

* Refactor login procedure around token auth

* Refactoring

* Add profile login screen

- Username / password values are not stored
- Just to fetch api token

* Login with basic auth

* Pass profile to API when connecting

* Remove _BASE_URL accessor

- Fixes URL caching bug

* Add more context to login screen

* Add helper functions for unit tests

- Change default port to 8000 (makes testing easier with local inventree instance)

* api.dart handles basic auth now

* fix api_test.dart

* Further test improvements

* linting fixes

* Provide feedback when login fails

* More linting

* Record user details on login, and display in "about" widget

* Fix string lookup

* Add extra debug

* Fix auth values

* Fix user profile test

test/setup.dart

@@ -1,6 +1,8 @@
 
 import "package:flutter/services.dart";
 import "package:flutter_test/flutter_test.dart";
+import "package:inventree/api.dart";
+import "package:inventree/user_profile.dart";
 
 // This is the same as the following issue except it keeps the http client
 // TestWidgetsFlutterBinding.ensureInitialized();
@@ -19,4 +21,78 @@ void setupTestEnv() {
       .setMockMethodCallHandler(channel, (MethodCall methodCall) async {
     return ".";
   });
+}
+
+// Accessors for default testing values
+const String testServerAddress = "http://localhost:8000/";
+const String testServerName = "Test Server";
+const String testUsername = "testuser";
+const String testPassword = "testpassword";
+
+
+/*
+ * Request an API token for the given profile
+ */
+Future<bool> fetchProfileToken({
+  UserProfile? profile,
+  String username = testUsername,
+  String password = testPassword
+}) async {
+
+  profile ??= await UserProfileDBManager().getProfileByName(testServerName);
+
+  assert(profile != null);
+
+  final response = await InvenTreeAPI().fetchToken(profile!, username, password);
+  return response.successful();
+}
+
+
+/*
+ * Setup a valid profile, and return it
+ */
+Future<UserProfile> setupServerProfile({bool select = true, bool fetchToken = false}) async {
+  // Setup a valid server profile
+
+  UserProfile? profile = await UserProfileDBManager().getProfileByName(testServerName);
+
+  if (profile == null) {
+    // Profile does not already exist - create it!
+    bool result = await UserProfileDBManager().addProfile(
+        UserProfile(
+          server: testServerAddress,
+          name: testServerName
+        )
+    );
+
+    assert(result);
+  }
+
+  profile = await UserProfileDBManager().getProfileByName(testServerName);
+  assert(profile != null);
+
+  if (select) {
+    assert(await UserProfileDBManager().selectProfileByName(testServerName));
+  }
+
+  if (fetchToken && !profile!.hasToken) {
+    final bool result = await fetchProfileToken(profile: profile);
+    assert(result);
+    assert(profile.hasToken);
+  }
+
+  return profile!;
+}
+
+
+/*
+ * Complete all steps necessary to login to the server
+ */
+Future<void> connectToTestServer() async {
+
+  // Setup profile, and fetch user token as necessary
+  final profile = await setupServerProfile(fetchToken: true);
+
+  // Connect to the server
+  assert(await InvenTreeAPI().connectToServer(profile));
 }