Add better support for csv files

[gabegma]

Description:

• Refactor the syntax tagging module to get rid of the tokenizer for counting tokens. I switched to counting words instead of sub-words, since this is what spacy provides, and it also makes sense. I lowered a bit the default value for a long_sentence to account for that.
• Add loading function for csv.

Checklist:

You should check all boxes before the PR is ready. If a box does not apply, check it to acknowledge it.

• ISSUE NUMBER. You linked the issue number (Ex: Resolve #XXX).
• PRE-COMMIT. You ran pre-commit on all commits, or else, you
  ran pre-commit run --all-files at the end.
• USER CHANGES. The changes are added to CHANGELOG.md and the documentation, if they impact
  our users.
• DEV CHANGES.
  • Update the documentation if this PR changes how to develop/launch on the app.
  • Update the README files and our wiki for any big design decisions, if relevant.
  • Add unit tests, docstrings, typing and comments for complex sections.

[gabegma]

@lindsaydbrin @JosephMarinier - I made some big refactoring to the syntax tagging module - you can look at that commit 9061507 individually to assess that it makes sense.

[lindsaydbrin]

Looks great! Big fan of the syntax tagging refactoring. 😁 Thanks!

[JosephMarinier]

Beautiful! 👍