Use shlex.split() to split pylint flags

[hfrentzel]

Some pylint flags may have spaces in them. For example --init-hook="import sys; sys.path.append(...". Beginning in v1.7.0 I started seeing this error when running the server

"pylsp.plugins.pylint_lint - Error calling pylint: 'Traceback (most recent call last):
  File \"<string>\", line 1, in <module>
  File \"/home/hfrentzel/.local/lib/python3.9/site-packages/pylint/lint/run.py\", line 132, in __init__
    args = _preprocess_options(self, args)
  File \"/home/hfrentzel/.local/lib/python3.9/site-packages/pylint/config/utils.py\", line 271, in _preprocess_options
    cb(run, value)
  File \"/home/hfrentzel/.local/lib/python3.9/site-packages/pylint/config/utils.py\", line 167, in _init_hook
    exec(value)  # pylint: disable=exec-used
  File \"<string>\", line 1
    \"import
           ^
SyntaxError: EOL while scanning string literal
'
"

The issue is that the --init-hook flag is being split up incorrectly when passed to pylint. This PR switches to using shlex.split() instead of just a normal string split() to split the args as a shell would.

[ccordoba12]

Looks good to me, thanks for your contribution @hfrentzel!