Design: Disable "Add device" if 2FA for a location is enabled

**Describe the bug**
The user can still create a manual/vanilla WG config even if 2FA enforced.

This allows to connect without having to use TOTP

**To Reproduce**
Steps to reproduce the behavior:
1. Create a location with required MFA
2. Add some user
3. Add TOTP to the user
4. Add a new device
5. Create a manual WG client
6. User can connect without using TOTP

**Expected behavior**
That users cannot connect without using TOTP -> Do not allow to add vanilla WG configs

**Version information**
- Defguard Core version: v0.9.0
- On any browser

**Screenshots**


**Additional context**
I'm not familiar with React (or ts/js at all), but it _seems_ to me that having some sort of check in: https://github.com/DefGuard/defguard/blob/c6f2d94fe033048c63141d0cbf70663f674c28b0/web/src/pages/addDevice/steps/AddDeviceSetupMethodStep/AddDeviceSetupMethodStep.tsx#L94 to not show the card if MFA is enabled should work.

Maybe a cleaner approach is just to skip to the next step if MFA is required with the "remote desktop activation" already selected for you and skip that step altogether