Say "term" when the pp end date is constrained by the term

closes LS-2891
flag=pace_plans

test plan:
  - in a course with a pace plan
  - in settings, set Participation to "Course" and enter dates
  - go to pace plans and click Show Projections, uncheck
    Required Completion... checkbox if checked
  > expect the caption under End Date to say
    "Required by course end date"
  - create a term if you don't have one
    - see /accounts/:id/terms
  - from course settings, set Term to be a term with an end date
  - go to pace plans and click Show Projections
  > expect the caption under End Date to say
    "Required by term end date"
  - check Require Completion by Specified End Date
  > expect the caption to say
    "Required by specified end date

Change-Id: I132188385976e5d27142b472dfb3b5465aa803c7
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/282876
Reviewed-by: Jackson Howe <[email protected]>
QA-Review: Jackson Howe <[email protected]>
Product-Review: Ed Schiebel <[email protected]>
Tested-by: Service Cloud Jenkins <[email protected]>

ui/features/pace_plans/react/components/header/projected_dates/__tests__/projected_dates.test.tsx

@@ -129,6 +129,25 @@ describe('ProjectedDates', () => {
       expect(getByTestId('paceplan-date-text').textContent).toStrictEqual('December 31, 2021')
     })
 
+    it('shows term end date text', () => {
+      window.ENV.VALID_DATE_RANGE = {
+        end_at: {date: COURSE.end_at, date_context: 'term'},
+        start_at: {date: COURSE.start_at, date_context: 'term'}
+      }
+      const plan = {
+        ...defaultProps.pacePlan,
+        hard_end_dates: false,
+        start_sate: '2022-01-03',
+        end_date: undefined
+      }
+      const {getAllByText, getByTestId} = renderConnected(
+        <ProjectedDates {...defaultProps} pacePlan={plan} />
+      )
+      expect(getAllByText('Required by term end date').length).toBeTruthy()
+      // expect the term end date
+      expect(getByTestId('paceplan-date-text').textContent).toStrictEqual('December 31, 2021')
+    })
+
     it('shows specified end date input', () => {
       const {getAllByText, getByDisplayValue} = renderConnected(
         <ProjectedDates {...defaultProps} />

ui/features/pace_plans/react/components/header/projected_dates/projected_dates.tsx

@@ -146,7 +146,11 @@ export const ProjectedDates: React.FC<ComponentProps> = ({
     endDateInteraction = planPublishing ? 'disabled' : 'enabled'
   } else if (ENV.VALID_DATE_RANGE.end_at.date) {
     endDateValue = ENV.VALID_DATE_RANGE.end_at.date
-    endHelpText = I18n.t('Required by course end date')
+    if (ENV.VALID_DATE_RANGE.end_at.date_context === 'course') {
+      endHelpText = I18n.t('Required by course end date')
+    } else {
+      endHelpText = I18n.t('Required by term end date')
+    }
     endDateInteraction = 'readonly'
   } else {
     endDateValue = projectedEndDate