Barcode scanner updates (#562)

* Add BUILDING.md

* Replace scaning library

- Out with qr_code_scanner
- In with flutter_zxing

* Update specs for jdk / kotlin / gradle

- NFI what this all means?

* Refactor barcode scanning widget

* Refactor barcode overlay

* Add handlers

* Update release notes

* Fix AppBar color

* Enhance attachment widget

* remove unused import

* Improved icon

* Select theme from main drawer

assets/release_notes.md

@@ -1,6 +1,7 @@
-### 0.17.0 - November 2024
+### 0.17.0 - December 2024
 ---
 
+- Improved barcode scanning with new scanning library
 - Enhanced home-screen display using grid-view
 - Improvements for image uploading
 - Provide "upload image" shortcut on Purchase Order detail view