MetersetMap GUI, network connection error for one site impacts all sites in iCom section

[SimonBiggs]

If a certain directory within the MU Density config isn't able to be found (for example due to a network issue at one site), then the application stops working (even for sites where network connectivity has no issues).

[SimonBiggs]

This can be fixed by splitting iCOM out by site instead of checking the iCOM for all sites at once.