118 - Implement shared album feature (#124)

* New features 
  - Share album. Users can now create albums to share with existing people on the network.
  - Owner can delete the album.
  - Owner can invite the additional users to the album.
  - Shared users and the owner can add additional assets to the album.
* In the asset viewer, the user can swipe up to see detailed information and swip down to dismiss.
* Several UI enhancements.

mobile/lib/modules/sharing/ui/album_action_outlined_button.dart

@@ -0,0 +1,36 @@
+import 'package:flutter/material.dart';
+
+class AlbumActionOutlinedButton extends StatelessWidget {
+  final VoidCallback? onPressed;
+  final String labelText;
+  final IconData iconData;
+
+  const AlbumActionOutlinedButton({Key? key, this.onPressed, required this.labelText, required this.iconData})
+      : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.only(right: 8.0),
+      child: OutlinedButton.icon(
+        style: ButtonStyle(
+          padding: MaterialStateProperty.all<EdgeInsets>(const EdgeInsets.symmetric(vertical: 0, horizontal: 10)),
+          shape: MaterialStateProperty.resolveWith<OutlinedBorder>(
+            (_) => RoundedRectangleBorder(
+              borderRadius: BorderRadius.circular(25),
+            ),
+          ),
+          side: MaterialStateProperty.resolveWith<BorderSide>(
+            (_) => const BorderSide(width: 1, color: Color.fromARGB(255, 158, 158, 158)),
+          ),
+        ),
+        icon: Icon(iconData, size: 15),
+        label: Text(
+          labelText,
+          style: const TextStyle(fontSize: 12, fontWeight: FontWeight.bold, color: Colors.black87),
+        ),
+        onPressed: onPressed,
+      ),
+    );
+  }
+}