Add Show Course Staff option and exclude all course roles by default (#168)

* Show Course Role Members

* add option to hide FilterBadge value for boolean filters

* chore: bump package to 1.4.20

Co-authored-by: Nathan Sprenkle <nsprenkle@edx.org>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@edx/frontend-app-gradebook",
-  "version": "1.4.19",
+  "version": "1.4.20",
   "description": "edx editable gradebook-ui to manipulate grade overrides on subsections",
   "repository": {
     "type": "git",