Until now we have only allowed to use and setup 'default bearers' (in
4G) or 'primary contexts' (in 2G/3G).
We can define a couple of additional bearer types, though:
* The 'dedicated bearers' (in 4G) or 'secondary contexts' (in 2G/3G),
which are associated to a specific default/primary one, but which
provide specific QoS settings configured via traffic flow templates.
* The 'initial default EPS bearer', which is a special case of default
bearer in LTE, which is automatically created and connected when the
modem is registered in the LTE network.
This commit introduces a new 'MMBearerType' enumeration that will be
associated to each bearer through a 'BearerType' property in the
org.freedesktop.ModemManager1.Bearer interface, showing what kind of
bearer/context this is.
By default, right now, all bearer objects created are 'default'
bearers.
Renamed `MMCommonBearerProperties' to `MMBearerProperties', and removed the
`MMBearerProperties' provided in libmm-glib. We'll just use the original one
from libmm-common always.
Renamed `MMCommonBearerIpConfig' to `MMBearerIpConfig', and removed the
`MMBearerIpConfig' provided in libmm-glib. We'll just use the original one
from libmm-common always.
