Update to create-react-app 4

- had to update eslint deps
- ran into https://github.com/palantir/blueprint/issues/4112
- had to move beta.svg out of static/
- had to fix prettier formatting changes
- ran into https://github.com/facebook/jest/issues/7780

test/env.js

@@ -14,5 +14,9 @@ module.exports = class CustomTestEnvironment extends Environment {
         if (this.global.TextDecoder === undefined) {
             this.global.TextDecoder = TextDecoder;
         }
+
+        // work around https://github.com/facebook/jest/issues/7780
+        this.global.Uint8Array = Uint8Array;
+        this.global.ArrayBuffer = ArrayBuffer;
     }
 };

test/index.ts

@@ -94,10 +94,10 @@ export function delay(ms: number): Promise<void> {
  * @param obj The object
  * @param id The property path
  */
-export function lookup(obj: object, id: string): string | undefined {
+export function lookup(obj: unknown, id: string): string | undefined {
     const value = id
         .split('.')
-        .reduce((pv, cv) => pv && (pv as Record<string, object>)[cv], obj);
+        .reduce((pv, cv) => pv && (pv as Record<string, unknown>)[cv], obj);
     if (typeof value === 'string') {
         return value;
     }