Embedded OpenSans Font and create Common Font Variables in DynamoModern.xml
Change current font to Embedded OpenSans for all UI control in DynamoView window
New Dark Theme UI for all control such as Button, Textbox, Checkbox, Dropdown
Implemented PreferenceSettings

Settings that became persistent:
1) Show Console
2) Connector Type
3) Fullscreen Watch Mode

Test cases included
(#362) Usability Data Collection Consent
Changes on Usability Data Collection not to set true if user press cancel even when checkbox is selected
Change Data Collection Consent prompt not to be at topmost.
Improvement on UI Textbox Watermark behavior
Code clean up and renaming variables
Fix for checkmark not appearing.
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into UserConsentPreference
Fixed merged commit, duplicated importing of BooleanToVisibilityConverter
Allow PreferenceSettings exception to be handled by application exception handler
Prototype UI for NodetoCode
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into PeanutButter
Integrate new astbuilder to NodeToCode
Merge remote-tracking branch 'upstream/ChocoButter' into UserConsentPreference

Conflicts:
	src/DynamoCore/UI/Views/DynamoView.xaml
Integrate node to code to EngineController
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into PeanutButter
Fix node deletion in nodetocode