(gen_changelog): group entries by scope

Description

Group Changelog entries by scope.

• Sort entries list by alphabetical order (case-insensitive).
• for each entry check if the previous one was the same scope.

Closes #24 (closed)

How to test it?

Generate the changelog locally.

For example (you can do in another way if you want):

1. Use personal fork of sight (to ensure that you will not push anything).
2. merge current dev into master.
3. tag master test_tag
4. run in the src folder path/to/sight-git/changelog/gen_changelog.py test_tag^ test_tag

Some results

Please check the following results:

ungrouped_entries

group_entries_by_scope