Adjust the catalog/report change confirm dialog text to warn user of data destruction when change specific order of catalogs

From https://github.com/GSA/openacr-editor/pull/55

> Data loss really should only occur if you are going from
>
> * 508 or 508 + WCAG --> WCAG
> * 508 + WCAG --> 508
>
> Should we warn folks if they are going from:
>
> * WCAG --> 508 + WCAG
> * 508 --> 508 + WCAG
>
> I think I'm missing one...
>
> Maybe we could congratulate them, but warn them that they might loose data if they go back? Not sure. That's probably an enhancement.

Start with the catalog/report change confirmation dialog discussed in pull request 55. Trace the order transitions listed in the issue and determine which changes can destroy data; done means the dialog text clearly warns users before destructive changes and appropriately describes the non-destructive transitions.

Written by the indexing model from the issue text.