Split embed redactor filter into multiple shared examples

What does this MR do?

Splits embed redactor filter examples for specs. This is to make it more explicit that the specs handle both redaction and non-redaction scenarios.

Closes #207544 (closed)

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done