refactor: Rename WiFi to WLAN for consistent terminology

Updated variable names, function names, and comments to replace "WiFi"
with "WLAN" throughout the codebase. This ensures alignment with
standardized terminology and improves clarity in functionality and
configuration handling. Adjusted related configurations and interface
mappings accordingly.

src/revpi_middleware/dbus_middleware1/system_config/interface_config.py

@@ -13,7 +13,7 @@ from .revpi_config import (
     configure_dphys_swapfile,
     configure_external_antenna,
     configure_gui,
-    configure_wifi,
+    configure_wlan,
     simple_systemd,
 )
 from ..dbus_helper import DbusInterface
@@ -94,7 +94,7 @@ AVAILABLE_FEATURES = {
     ),
     "revpipyload": FeatureFunction(simple_systemd, ["revpipyload.service"]),
     "bluetooth": FeatureFunction(configure_bluetooth, []),
-    "ieee80211": FeatureFunction(configure_wifi, []),
+    "wlan": FeatureFunction(configure_wlan, []),
     "avahi": FeatureFunction(configure_avahi_daemon, []),
     "external-antenna": FeatureFunction(configure_external_antenna, []),
 }