fix(client): clarify what progress reset includes

[huyenltnguyen]

Checklist:

• I have read and followed the contribution guidelines.
• I have read and followed the how to open a pull request guide.
• My pull request targets the main branch of freeCodeCamp.
• I have tested these changes either locally on my machine, or GitPod.

This PR updates the text in the progress reset modal to clarify what the action does.

Note: I'm not adding the big "WARNING!" text to the modal because it would bring inconsistency (the delete account modal doesn't have this text). We changed the reset modal to have its content displayed in danger color during the Modal migration, and I think this should suffice (we do communicate the critical level of the action through text, and not just text color, so this isn't an a11y concern).

Closes #53959

Screenshots

Before	After