Prevent excessive sanitization of AsciiDoc ouptut

What does this MR do?

Introduces a new sanitization filter AsciidocSanitizationFilter, based on Banzai::Filter::SanitizationFilter, with specific looser rules for Asciidoc.

Before	After

Resolves #63298 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Style guides

Performance 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