make it possible to update XSD schema in project controller after new
target PLC is added or removed.

For example:


...
import targets
targets.targets["PLC"] = {"xsd": os.path.join(self.customBeremizPath, "PLCtarget", xsd),
"class": lambda: PLC_target,
"code": {"plc_PLC_main.c": os.path.join(self.customBeremizPath, "PLCtarget", "plc_PLC_main.c")}
}

from ProjectController import ProjectController, GetProjectControllerXSD
ProjectController.XSD = GetProjectControllerXSD()

{
    "url":"ws://127.0.0.1:8888",
    "realm":"Automation",
    "ID":"wamptest",
    "password":"1234567890",
    "key":"ABCDEFGHIJ"
}