Resolve #1 "Port Interface", #8 "Port Coupling"

Adds:

• Port interface functions for InputPort and OutputPort.
• Functionality for connecting ports and signals, both via signals and ports.
• Tests that verifies that the functionality has been correctly implemented.
• Fixes to older code so that it works with the new interfaces.
• Minor functionality for connecting operations in their constructors.

Closes #1 (closed) and closes #8 (closed)

b_asic/graph_component.py

@@ -18,17 +18,17 @@ class GraphComponent(ABC):
     @property
     @abstractmethod
     def type_name(self) -> TypeName:
-        """Returns the type name of the graph component"""
+        """Return the type name of the graph component"""
         raise NotImplementedError
 
     @property
     @abstractmethod
     def name(self) -> Name:
-        """Returns the name of the graph component."""
+        """Return the name of the graph component."""
         raise NotImplementedError
 
     @name.setter
     @abstractmethod
     def name(self, name: Name) -> None:
-        """Sets the name of the graph component to the entered name."""
+        """Set the name of the graph component to the entered name."""
         raise NotImplementedError