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
Fix: MAGN-683 Switching tab eventually causes crash in undo
Fix for Dynamo Crashing when node preview is being mouse-overed (MAGN-497).
Prototype UI for NodetoCode
Fixed Hotkey for controlling background preview.

Adding a new property that take note of both boolean WatchEscapeIsDown and CanNavigateBackground for the hit test of the "Watch3DView".
Removed preview from nodes that are not suppose to have preview.
Merge pull request #730 from l2obin/HotkeyFixesBranch

Fixed Hotkey for controlling background preview.
Merge pull request #731 from SkyApple/RemovingPreviewFromSpecificNodes_ChocoButterUI

Removed preview from nodes that are not suppose to have preview.