Convert Id type fields to string before assigning to CustomMetadataValue

[kacrouse]

CustomMetadataValue only handles primitives, so it fails on relationship fields. The value just needs to be converted to a string before being assigned.

I've gotten it to work by changing line 140 to this: cmv.value = dsr.soapType == Schema.SoapType.ID ? String.valueOf(fieldValue) : fieldValue;

As far as I can tell this is the only type that needs special handling.

[afawcett]

Thanks @kacrouse for this fix, i have applied it. 👍