Add ExtendedCall to PLCObject as a replacement of RemoteExec and reflect it in eRPC interface.

ExtendedCall is a generic remote procedure call that runtime code can register to and that IDE extensions can call.
For example a fieldbus extension can use ExtendedCall to browse the fieldbus devices connected to the runtime.

Edit PLC program
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POU languages and type
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POU interfaces
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Global variables
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Located variables
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Resources, task and instances
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Copy-paste
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