Fix title max length and add more tests

[damiencarol]

This pull request fix few potential bugs on the size of title in findings for 3 parsers:

• AWS Prowler
• AWS Scout
• Scoutsuite

Also this pull request add unit tests for scout2 parser which doesn't exists (!)

[valentijnscholten]

Thanks, maybe we should implement something generic in models.py Finding.save()

[damiencarol]

@valentijnscholten you're right, it's better to do it in model. or after the call to get_findings(). Will make some modifications this way not in this PR I think as it will impact all parsers.