bump max per-page for temp enroll assign enrollments fetch

This commit updates the current maximum limit for the temporary
enrollments assign component enrollments API call from 50 to
100; this should temporarily help accounts that have 1 to 100
active enrollments.

closes FOO-4467
flag=temporary_enrollments

test plan:
- enable temporary enrollments feature flag
- find a recipient of temporary enrollment
- navigate to the assign screen
- verify that the max per-page is 100 for courses fetched
- this doesn’t add pagination, just a max per-page, which should
  satisfy the use case for now

[skip-crystalball]

Change-Id: Ib581caaff5e72bf5a128805357edfa28aee2454a
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/347396
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: August Thornton <august@instructure.com>
QA-Review: Michael Hulse <michael.hulse@instructure.com>
Product-Review: Michael Hulse <michael.hulse@instructure.com>

ui/shared/temporary-enrollment/react/types.ts

@@ -19,7 +19,7 @@
 export const MODULE_NAME = 'TempEnroll'
 
 export const ITEMS_PER_PAGE = 100
-export const MAX_ALLOWED_COURSES_PER_PAGE = 50
+export const MAX_ALLOWED_COURSES_PER_PAGE = 100
 
 export const TOOLTIP_MAX_WIDTH: string = '15rem'
 export const ENROLLMENT_TREE_SPACING: string = '1.75rem'