Fixes #225 - Use a properly defined user agent

* Set a proper user agent
* Add fallback when UA comes out nil
* Remove unused Bundle extension
* Return nil when asciification fails
* Add whitespace handling and further emoji test case
* Explicitly check if string is already in ASCII
* Rename factory to builder
* Use allSatisfy instead of reduce
* Use key path syntax

ElementX/SupportingFiles/target.yml

@@ -101,6 +101,7 @@ targets:
     - package: DesignKit
     - package: AnalyticsEvents
     - package: AppAuth
+    - package: DeviceKit
     - package: DTCoreText
     - package: KeychainAccess
     - package: Kingfisher