Upload Review page: UI Improvements

[atruskie]

Is your feature request related to a problem? Please describe.

User feedback for the review page noted that:

• The "Continue" button was seen as the next step in the process, i.e. to next step to address the issues. This is the incorrect interpretation.
• instructions about warnings and errors do not appear until the folders are expanded.
• the confirm dialog was not enough of a warning
  • You can't undo this step
  • We should warn about the acceptance rate.

Describe the solution you'd like

We should address these UX issues.

Describe alternatives you've considered

Maybe docs?

Additional context