Fix ux bugs in Admin Panel

[whitef0x0]

This PR fixes various bugs found in the Admin Panel

Description

The changes in the PR are as follows:

1. Remove "deletePreserved" logic so that form fields are not preserved after deletion if they have at least one response
2. Move from textAngular WSIWYG Editor to QuillJS to fix template variable rendering (in editor)
3. Move from regex-based parsing to HTML based parsing for email notification template engine
4. Rename hideFooter in form model to showFooter
5. Add pre-save logic to remove 'deletedPreserved' fields from forms
6. Changed mockTransport from "Stub" to "jsonTransport" for send-email-notifications tests
7. Updated client-side dependencies from Angular 1.4 to Angular 1.6
8. Fixed bug that prevented proper merging of frontend and backend coverage stats
9. Added (angular) unit tests for VerifyController, SettingsController and PasswordController
10. Added a loading indicator for Configuration Panel's save button
11. Removed extraneous console.log() statements from server and client side
12. Changed from numerical to alphabetical shortcuts for multiple choice field (see https://github.com/tellform/tellform/issues/232)
13. Fixed form field scroll spy bugs by changing from using $on('scroll') to using ng-scrollspy library
14. Simplified route forwarding logic in core.client.routes.js
15. Fixed missing and incorrect translations
16. Fixed blank page bug when refreshing the edit profile view
17. Removed irrelevant tests
18. Fixed duplicate form bug
19. Fixed bug that caused view to transition when opening delete form modal on the admin page
20. Fixed bug that caused responses to be set to null when duplicating a form
21. Separated css for admin pages into files for each tab directive
22. Fixed bug that allowed the form field placeholder to be draggable
23. Added default fallback values for analytics data
24. Fixed bug that wouldn't update fieldIcon when form fields were rearranged/dragged
25. Restyled the "share" admin tab
26. Made sub-tabs of "share" admin tab routable
27. Changed language dropdown of create new form modal to use entire word of language instead of language codes
28. Disabled respondent notification toggle switch when email field is not present
29. (Partially) removed flickering when switching between configure panel sub tabs
30. Updated server-side and client-side tests
31. Removed unnecessary 'users' service and replace it with an $http.put function call
32. Removed "social-accounts" settings view
33. Set button label "copied" after copy button in share tab is clicked

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[coveralls]

Coverage increased (+33.4%) to 60.049% when pulling 0a4b831 on fixUXBugs into 9ff247f on 2.20.

[coveralls]

Coverage increased (+33.9%) to 60.534% when pulling 65a4e3f on fixUXBugs into 9ff247f on 2.20.

[coveralls]

Coverage increased (+17.8%) to 44.509% when pulling f92d6f4 on fixUXBugs into 9ff247f on 2.20.

[coveralls]

Coverage increased (+17.8%) to 44.509% when pulling 22ff9ca on fixUXBugs into 9ff247f on 2.20.

[coveralls]

Coverage increased (+17.9%) to 44.606% when pulling d1c9527 on fixUXBugs into d8c5b00 on 2.20.

[coveralls]

Coverage increased (+17.9%) to 44.579% when pulling 9723d57 on fixUXBugs into d8c5b00 on 2.20.

[coveralls]

Coverage increased (+17.8%) to 44.482% when pulling 2c59809 on fixUXBugs into d8c5b00 on 2.20.