refactor: rename EndpointBase to SocketBase

Because 'endpoint' is also used in the messages, the name 'socket' is more descriptive.

ref: N25B-168

src/robot_interface/endpoints/socket_base.py

@@ -0,0 +1,38 @@
+from abc import ABCMeta
+
+
+class SocketBase(object):
+    __metaclass__ = ABCMeta
+
+    name = None
+    socket = None
+
+    def __init__(self, name):
+        """
+        :param name: The name of the endpoint.
+        :type name: str
+        """
+        self.name = name
+        self.socket = None
+
+    def create_socket(self, zmq_context, socket_type, port):
+        """
+        Create a ZeroMQ socket.
+
+        :param zmq_context: The ZeroMQ context to use.
+        :type zmq_context: zmq.Context
+
+        :param socket_type: The type of socket to create. Use zmq constants, e.g. zmq.SUB or zmq.REP.
+        :type socket_type: int
+
+        :param port: The port to use.
+        :type port: int
+        """
+        self.socket = zmq_context.socket(socket_type)
+        self.socket.connect("tcp://localhost:{}".format(port))
+
+    def close(self):
+        """Close the ZeroMQ socket."""
+        if not self.socket: return
+        self.socket.close()
+        self.socket = None