Adds cohorts as valid bulk email targets.

TNL-4356

Allows multiple bulk email targets to be specified at once.

-The previous "All" option has been split into "Staff" and "Learners"
-The backend changes made here lay the groundwork for cohort emailing
-The data migration, 0005, is somewhat large and requires deploy attention
-Tests have been updated
-Numerous safe-commit-linter fixes are included

Don't use symlinks to include node_modules

Fix incorrectly scoped selector.

  - Corrected the direction of the English equations
  - TNL-3798: Removed the greek letters
  - The equal (=) button is now the default submit button in the calculator, instead of the help button
  - TNL-3798: Removed the subscript note
  - Added some comments for the translators in the calculator
  - Using `fixed` position for the calculator for best mobile/desktop look

Following have been done
1- Change the structure of the course navigation Menu HTML
2- Add some basic styling
3- Add basic JS for html rendering
4- Update tests according to new structure

AC-76

Tooltip hint on the calculator apears on the mouse hover so the links
on the tooltip could not be accessed

tnl-944

Added bokchoy tests and assets (csv files) for CSV auto reg and enrollment.
Set the env flag "ALLOW_AUTOMATED_SIGNUPS": true in bok_choy.env.json

Resolved quality issues.

resolved cherry pick conflicts

Improved bokchoy tests as per code review suggestions.

added the BDD in the docstrings for all the test scenarios

changed the bok choy test string

Improved bokchoy tests as per further code review suggestions.

Made a MembershipPageAutoEnrollSection a separate PageObject.

add license to a11y_tools.js

add tests, some reorganization of js tests

skip "toBeFocused" tests for now

[LMS-57]

keep log_event for compatibility

that were causing phantomjs interpreter to fail
with undefined method error.

when we don't have an ajax url