Refactor of User-Reported Dataset Error Emails

[hujambo-dunia]

• This is PR "Part 1 of 2" to address the [feature request] There seems to be no way to report a 'tool error' if that tool is apply rules #17560 issue.
• This PR (mostly front-end changes) handles much needed: (1) decoupling of View vs. Controller and (2) object-oriented abstraction.
• The PR "Part 2 of 2" (mostly back-end changes) handles API abstraction to allow for user-submitted error reporting on other Objects (eg. 'Tools').

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[jdavcs]

Can you, please, reword the commit description as per our guidelines (https://github.com/galaxyproject/galaxy/blob/dev/CONTRIBUTING.md#how-to-contribute, item 6) - i.e., short imperative sentence, then space, followed by detailed description when needed). It really matters for working with git history and for release notes.