Static init functions are functions that initialize resources
or monitor daemons without needing any contextual information,
such as a CcPanel instance or access to a CcShell implementation.

These functions are meant to be used for monitoring a panel's
visibility, when it makes sense. Usually, panels that represent
hardware that potentially is not available or is not supported
should hide itself.

Following this commit, the Wi-Fi panel panel will be adapted as
the first user of this new API. Other panels that require this
functionality will be adapted later.