Windows Desktop Client 3.0.0-beta3 released

This release focuses on several bugs discovered in beta 2:

* Resolve bug where the client won't actually close (Fixes #49 and #53)
* Add code analysis to CI build process (follows Flutter best-practices)

This release has the following features:


* Show warning if there are no downloads
* Remove unneeded libraries (saves approximately 50% of installation size)

As always you can download the latest Version 3 beta client from GitHub (https://github.com/bluecherrydvr/unity/releases)