Some firmware versions return an empty string for the revision when
using the device caps MBIM request, so use AT commands as a fallback
in case this happens.
Instead of creating libmm-plugin* and libmm-shared* libraries that are
dlopen()-ed on runtime, allow incorporating all plugins into the
daemon binary itself.
This makes the startup of the daemon much faster and also avoids
issues with builds that require linker namespace isolation.
Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/674
We are going to allow including the plugin sources built within the
ModemManager daemon binary; moving the sources within the daemon
sources directory makes it easier.