Add Python Version Check to Python Scripts

ISSUE #204 : Running on versions prior to 3.10 will fail, due to
the use of `match` statements. Other parts of the script assume
a recent Python also, and the system as a whole expects a recent
version of Ubuntu.

`pythonCheck.py` polls `sys.version_info` to detect the in-use
version of Python. If the version is prior to 3.10, it bails out
with the message "LibreQoS requires Python 3.10 or greater".

This should help with outdated OS detection in general.

src/pythonCheck.py

@@ -0,0 +1,14 @@
+import os
+
+def checkPythonVersion():
+    # Perform a version check
+    import sys
+    print("Running Python Version " + sys.version)
+    version_ok = True
+    if sys.version_info[0] < 3:
+        version_ok = False
+    if sys.version_info[0]==3 and sys.version_info[1] < 10:
+        version_ok = False
+    if version_ok == False:
+        print("LibreQoS requires Python 3.10 or greater.")
+        os._exit(-1)