Add rich based spinner

[ichard26]

Broken out of #13450. Our legacy spinners can't be used for that PR because they require that their spin() method is called manually (and thus are only really functional with the subprocess utility). Instead, let rich handle the updates in the background for us.

Can be tested manually like so:

import time
import logging.config  # this is a bug with pip's logging stack
from pip._internal.cli.spinners import open_rich_spinner
from pip._internal.utils.logging import setup_logging

setup_logging(0, no_color=False, user_log_file=None)
with open_rich_spinner("doing work"):
		time.sleep(2)
try:
		with open_rich_spinner("doing work"):
				1/0
except BaseException:
		pass
try:
		with open_rich_spinner("doing work"):
				raise KeyboardInterrupt
except BaseException:
		pass

[notatallshaw]

This looks good.

I would be tempted to rename PipRichSpinner to _PipRichSpinner to make it clear it shouldn't be accessed externally.

Also because the PipRichSpinner is running in a thread, if somehow something other than Live called render or finish there could be thread safety issues, but because the context manager doesn't even return the Live object I think this should never happen.

[ichard26]

There are two ways thread safety issues can arise:

• Multiple threads are calling render() or finish() directly, as you've mentioned, the API makes this impossible
• Multiple threads are writing to the terminal at once, leading to interwoven output. This can be avoided as long as the same console instance is used globally. This is easy to achieve using the get_console() helper that I added in PR Installation progress bar ✨ #13220.

In addition, this code is going to be rolled out in a opt-in basis so there are unexpected issues, they can be addressed at a later point.

Thanks for the review!