Prologix support for both USB and ethernet versions

[bobmcnamara]

Support added for Prologix GPIB adapters, both USB and ethernet. Examples of usage:

import pyvisa
rm = pyvisa.ResourceManager()
prlgx = rm.open_resource("PRLGX-TCPIP::169.254.1.80::INTFC")
instr = rm.open_resource("GPIB::17::INSTR")
instr.query("*IDN?")

Or for USB version:

import pyvisa
rm = pyvisa.ResourceManager()
prlgx = rm.open_resource("PRLGX-ASRL::/dev/cu.usbserialXXX::INTFC")
instr = rm.open_resource("GPIB::17::INSTR")
instr.query("*IDN?")

• [n/a] Closes # (insert issue number if relevant)
• Executed ruff check . && ruff format -c . --check with no errors
• [ToDo] The change is fully covered by automated unit tests
• [ToDo] Documented in docs/ as appropriate
• Added an entry to the CHANGES file

[MatthieuDartiailh]

Thanks for the PR. I will do my best to review it by early next week.

[MatthieuDartiailh]

I left a bunch of minor stylistic comments.

However I think there is one more serious issue related to thread safety that need to be addressed. When setting the gpib_addr of the interface we need to be sure that no thread will modify it before the interface is done doing the job we need it to do.