HTML API: Abort on text nodes requiring reconstruction

[dmsnell]

Trac ticket: Core-60455

Alternative to #6054

When reaching text nodes that require creating elements during active format reconstruction, aborts the HTML Processor.

This prevents progressing into a document where the text nodes would change the structure and affect breadcrumbs. Until the HTML Processor properly supports text nodes this makes it possible to continue operating safely.

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[github-actions]

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[dmsnell]

Closing this because I don't think that the approach is sound. Favoring the more comprehensive approach of tracking every token in the HTML Processor, in #6054