scripts: Renamed summary.py -> csv.py

This seems like a more fitting name now that this script has evolved
into more of a general purpose high-level CSV tool.

Unfortunately this does conflict with the standard csv module in Python,
breaking every script that imports csv (which is most of them).
Fortunately, Python is flexible enough to let us remove the current
directory before imports with a bit of an ugly hack:

  # prevent local imports
  __import__('sys').path.pop(0)

These scripts are intended to be standalone anyways, so this is probably
a good pattern to adopt.

scripts/code.py

@@ -12,6 +12,9 @@
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
+# prevent local imports
+__import__('sys').path.pop(0)
+
 import collections as co
 import csv
 import difflib