[tools] [messages] Add simple CSV converter

Closes: #100

tools/csv-convert.py

@@ -0,0 +1,26 @@
+#! /usr/bin/python3
+
+# SMS Import / Export: a simple Android app for importing and exporting SMS messages from and to JSON files.
+# Copyright (c) 2023 Thomas More
+#
+# This file is part of SMS Import / Export.
+#
+# SMS Import / Export is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# SMS Import / Export is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with SMS Import / Export.  If not, see <https://www.gnu.org/licenses/>.
+
+# Written for https://github.com/tmo1/sms-ie/issues/100
+
+import csv
+import json
+
+print(json.dumps(list(csv.DictReader(open(0, newline=''))), indent=2))