feat: sort comments in explorer by selected location

[croesnick]

Solves GH-121

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Other... Please describe:

What is the current behavior?

See GH-121

What is the new behavior?

Sorts comments in the comment explorer ascending by location information.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[croesnick]

Ouch. This could have been a bit easier if I would have seen #38 before 🙈
My changes so only bring this feature to the comment explorer. My underlying believe, however, still holds true: the necessity to split the CSV model from the internal data model (cf. #123).