feat(protonvpn): feature filters (#2182)

- `SECURE_CORE_ONLY`
- `TOR_ONLY`
- `P2P_ONLY`

Dockerfile

@@ -140,6 +140,9 @@ ENV VPN_SERVICE_PROVIDER=pia \
     SERVER_NAMES= \
     # # ProtonVPN only:
     FREE_ONLY= \
+    SECURE_CORE_ONLY= \
+    TOR_ONLY= \
+    P2P_ONLY= \
     # # Surfshark only:
     MULTIHOP_ONLY= \
     # # VPN Secure only: