Sanitize more quotation marks, option to export lowercase

[hakankvist]

Add more quotation marks to default configuration for sanitizer: "'", "’", "´", "`"

Add new option to export all files/paths as lowercase.

Summary

When exporting a confluence area, I noticed that several documents where created included quotation marks.
These can cause problems when further post processing the exported files, like running them through a shell script.
In order to avoid these problems.

Also added a new option to make the filenames lowercase. When working with files some parties prefers working with files in lowercase only. (On Linux the casing matters, on Windows it doesn't)

Test Plan

Tested running export on internal confluence.
Added additional unit test to cover the downcasing case.

[hakankvist]

Unfortunately RUFF didn't like some of the new quotation marks added, so I had to exclude that check for that line.

More information about the warning:
https://docs.astral.sh/ruff/rules/ambiguous-unicode-character-string/