[MICROBA-1621]
* Fix display bug for the error Alert component found during test writing
* Add tests for BulkEmailTaskHistory component
* Fix bug with a column name in the bulk course email content history table
* Add tests for the BulkEmailContentHistory component
* Add tests for the BulkEmailPendingTasks component
- Wires up the BulkEmailForm to be able to actually send email tasks to
the instructor api
- Adds testing for the BulkEmailForm, as well as BulkEmailTool itself
- Does some cleanup, and adds some additional testing tools as needed
[MICROBA-1621]
* Add a table to the BulkEmailTaskHistory component of the task manager.
* Add a table to the BulkEmailPendingTasks component of the task manager.
* Extract messages to messages.js.
* Add custom hook used to make REST API calls to edx-platform on a regular cadence (every 30 seconds).
* Use the new hook in BulkEmailPendingTasks to retrieve pending instructor tasks for display in a table.
* Create a new BulkEmailHistoryTable component to cutdown on code duplication between task manager componenets that display tables.
* Refactor existing components to use the new BulkEmailHistoryTable component (and reduce amount of duplicate code in the task manager)
* Use a StatefulButton (over a regular button) to show a spinner/loading icon when fetching data for our tables.
[MICROBA-1621]
* Add table that displays info about previously sent bulk course email messages through our tool.
* Add modal to view the contents of previously sent messages.
* Extract strings to a dedicated `messages.js` file to help make the `BulkEmailContentHistory.jsx` file more readable.
[MICROBA-1621]
* Add support to the Instructor Dashboard `list_instructor_tasks`, `list_email_content`, and `list_background_email_tasks` REST API endpoints of edx-platform.
This will protect the bulk email tool and ONLY the bulk email tool from non-staff users if they know the direct URL. this will not protect the entire app from non-staff entirely.
[MICROBA-1621]
* Adds a section for the pending tasks section of the task manager
* Adds a section for the bulk course email task history data
* Adds a section for the bulk course email content history data
