feat: integrate two factor authentication (#626)

* feat: integrate SNJS MFA with web

* fix: create rudimentary typings file for qrcode.react

* chore: lint fixes

* fix: address PR feedback

* fix: address PR feedback

* fix: address PR feedback 2

* fix: replace spread props on TwoFactorAuthWrapper component

* chore: change null check to undefined check

app/assets/javascripts/preferences/panes/two-factor-auth/MfaProps.ts

@@ -0,0 +1,17 @@
+export interface MfaGateway {
+  getUser(): { uuid: string; email: string } | undefined;
+
+  isMfaActivated(): Promise<boolean>;
+
+  generateMfaSecret(): Promise<string>;
+
+  getOtpToken(secret: string): Promise<string>;
+
+  enableMfa(secret: string, otpToken: string): Promise<void>;
+
+  disableMfa(): Promise<void>;
+}
+
+export interface MfaProps {
+  mfaGateway: MfaGateway;
+}