adding bandwidth information in mm-dbus interface
for the serving cell. In serving cell, the details
on whether the pcell/scell are from MCS or SCG is
also updated.

Co-author: Shilpa Shivakumar

This new method allows querying the modem for information about the
current serving cell(s) as well as any other neighboring cell that may
be found.

The information for the cells is given in an array of dictionaries,
where each element of the dictionary is a new dictionary itself.

Each cell type has a different set of properties that may be given in
the dictionary, and some of those properties in each type are also
applicable under certain conditions (e.g. only applicable to the cell
if it's a 'serving' cell instead of 'neighboring').

The API documentation explains in detail what is expected in each
case.

Sometimes it's useful to know how a given stored profile was created,
so devices can store and report this kind of information.

The 'allow-roaming' setting should be considered deprecated for 3GPP
devices that support the new 'roaming-allowance' setting, which is
much more detailed (as it allows to differentiate between partner and
non-partner networks) and may also be stored as part of a profile.

In 5G capable devices, which can support multiple types of access
types (either 3GPP or non-3GPP), the UE may request to use a 3GPP
access type exclusively, prefer a 3GPP access type, or just report no
preference.

When supported, this field may also be part of the settings that can
be stored as part of a profile.