[WWAN] [Mobile Network] Add option in UI to select SIM slot

Some WWAN Module supports both Physical SIM and e-SIM . However , user needs to change SIM slot manually using "mmcli -m any --set-primary-sim-slot=1 or 2" based on SIM which user wants to use .

In Windows, there is option available as shown in below image:

However in Linux , this option is missing . So ,suggestion is to add it in "Mobile Network" Settings :

Note:

SIM1 is Physical SIM

SIM2 is e-SIM

Any comment regarding this will be helpful.

Thank you !