[ENG-1412, 1413, 1414] Fixes CSV upload modal bugs

[vsreekanti]

Describe your changes and why you are making these changes

The CSV upload modal had a few bugs that made it confusing to use. This PR fixes the following:

• ENG-1412: The modal was way too narrow, so you couldn't see any of the data you uploaded.
• ENG-1413: The modal didn't close after upload, so it seemed like nothing actually uploaded.
• ENG-1414: The preview showed an ID column that wasn't included in the original data.

There's still a tiny bug where I'd like to have the dialog expand to show the full 5 rows, but I couldn't fix that quickly.

Related issue number (if any)

See above

Checklist before requesting a review

• I have created a descriptive PR title. The PR title should complete the sentence "This PR...".
• I have performed a self-review of my code.
• I have included a small demo of the changes. For the UI, this would be a screenshot or a Loom video.
• [N/A] If this is a new feature, I have added unit tests and integration tests.
• [N/A] I have run the integration tests locally and they are passing.
• [N/A] I have run the linter script locally (See python3 scripts/run_linters.py -h for usage).
• All features on the UI continue to work correctly.
• Added one of the following CI labels:
  • run_integration_test: Runs integration tests
  • skip_integration_test: Skips integration tests (Should be used when changes are ONLY documentation/UI)

[agiron123]

Looks great!