Added derive units to core

Derive units are now available in the core and has their relevant input
values routed and outputs are looped back into the core router

Fixed the dlpak manifest which had no signal descriptors

test/manual/process.py

@@ -0,0 +1,11 @@
+from dynalab_core.protocols.packets.data import ValueDescriptor
+from dynalab_core.protocols.packets.handshake import SignalDescriptor
+
+
+def process(
+    a: ValueDescriptor, b: ValueDescriptor, r: SignalDescriptor
+) -> ValueDescriptor:
+    val = ValueDescriptor(
+        signal_id=r.id, value=a.value * b.value, timestamp=a.timestamp
+    )
+    return val