[wificond] Move to wificond namespace

Move the rest of the code to the wifi.wificond namespace from the
wifi namespace. Cleanup since wificond is outside the Wi-Fi module.

Non-functional change.

Bug: 140062898
Test: atest android.net.wifi
Test: atest com.android.server.wifi
Test: ./system/connectivity/wificond/runtests.sh
Test: (CTS) atest android.net.wifi.cts
Change-Id: I64535329edbf96b1f1a0ddc0d85ebe99f9343c76