Add bufsize argument to TCPInterface.recv()

Default to 4096, the reasonable example value from upstream docs, which is
commonly used in existing agents.

socs/agents/cryomech_cpa/drivers.py

@@ -53,7 +53,7 @@ def get_data(self):
         Gets the raw data from the PTC and returns it in a usable format.
         """
         self.send(self.buildRegistersQuery())
-        data = self.recv()
+        data = self.recv(1024)
         data_flag, brd = self.breakdownReplyData(data)
 
         return data_flag, brd

socs/tcp.py

@@ -123,13 +123,18 @@ def _check_ready(self):
         if not sel.select(self.timeout):
             raise ConnectionError("Socket not ready to read. Possible timeout.")
 
-    def recv(self):
+    def recv(self, bufsize=4096):
         """Receive response from the device.
 
         This method will check if the socket is ready to be read from before
         performing the recv. If there is no data to read, or the socket is
         otherwise unready an exception is raised.
 
+        Parameters
+        ----------
+        bufsize : int
+            Amount of data to be recieved in bytes. Defaults to 4096.
+
         Returns
         -------
         ``str`` or ``bytes``
@@ -143,7 +148,7 @@ def recv(self):
 
         """
         self._check_ready()
-        data = self.comm.recv(1024)
+        data = self.comm.recv(bufsize)
         return data
 
     def __del__(self):