Fix distutils, add alternate db support

[alperkocatas]

This PR includes two changes:

add a --dbname=<database_name> option

This enables setting up an alternative database instead of using the default postgres database. Usage with new option to create a test database and install citus there:

citus_dev make test-cluster --size=2 --dbname=test

fix distutils exception:

When ran on Ubuntu 24.04 lts with python version 3.12.3, we get the following exception:

Traceback (most recent call last):
  File "/home/alperkocatas/citusdata/tools/citus_dev/./citus_dev", line 32, in <module>
    import distutils.spawn
ModuleNotFoundError: No module named 'distutils'

(.venv) alperkocatas@kocatas-db01:~/citusdata/tools/citus_dev$ pip3 install distutils
ERROR: Could not find a version that satisfies the requirement distutils (from versions: none)
ERROR: No matching distribution found for distutils

It looks like distutils is deprecated for newer versions of python, so, we can use shutil instead of that.