[stdlib] Remove some `# CHECK` and refactor `test_print.mojo`

[gabrieldemarmiesse]

Related to #2024

Some tests in test_print.mojo are not related to printing at all. It's more testing the string conversion. So I took the liberty of putting them in the right files. This also helped remove some # CHECK as removing those when testing the print() function is really hard.

[ConnorGray]

Hey @gabrieldemarmiesse we have our new merging infrastructure set up, but in order to merge this branch it will need to be rebased to include the "baseline" commit that our new syncing tool uses.

Could you:

# Ensure you have the latest `nightly` branch update
$ git checkout nightly
$ git pull

# Rebase your branch so its history includes all of `nightly`
$ git checkout <this PRs branch>
$ git rebase nightly

This will ensure this branch includes this baseline commit in its history.

Once this is done, I'll be able to proceed with merging this PR 🙂

Thank you in advance, and apologies for the wait!

[gabrieldemarmiesse]

Sure thing. I'll do it for all my PRs in one go :)

[ConnorGray]

Perfect, thank you so much! 🙌

[gabrieldemarmiesse]

All PRs rebased :)

[ConnorGray]

✅🟣 This contribution has been merged 🟣✅

Hi @gabrieldemarmiesse thanks for this contribution, and updating all of your PRs!

As mentioned, we're moving to a new infrastructure for merging contributions to Mojo (we're using a tool called Copybara), and your contribution has now been merged into our internal copy of the Mojo Standard Library.

The changes in this PR will appear here in the mojo repo nightly branch when we do our next outbound synchronization at the time that the next Mojo nightly is released. That should happen later today but could be delayed until Monday.

Thank you so much for helping us burn down 🔥 the FileCheck uses! :)

Please let me know if you have any questions or concerns.

[gabrieldemarmiesse]

Thanks for all the work around making the nightly available more frequently!

While this is great to see much faster the internal commits publicly, we will see the external commits be updated every 24 hours if I understand correctly, instead of seeing them in nightly instantly. This can be a big pain if we have multiple pull requests touching the same piece of code, we can do only one rebase and one merge every 24 hours. Would it be possible to refresh the public branch as frequently as possible? If possible every commits if this is automatic?

Otherwise making PRs that depends on other PRs will be a pain (and it's also more difficult to develop if we can't see which PR has been merged during the day and we can't pull those changes).

While this is more convenient for the Modular staff, I hope this won't be more inconvenient than before for the external contributors who make frequent pull requests