fix: wrap overflowing MathJax content in rich text

[TahaKhan998]

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Description

Closes CERNDocumentServer/cds-rdm#695

The issue here was not that $...$ was failing to be recognized as LaTeX. I checked this locally and MathJax was already enabled and rendering those expressions correctly. The actual problem was that long or malformed inline MathJax output could overflow its container and push the layout out of bounds.

This PR fixes that as a layout and wrapping issue in invenio-app-rdm.

What changed

1. Added min-width: 0 to .main-record-content so the main content column can shrink properly inside the flex layout instead of being forced wider by long MathJax content.
2. Extended the shared wrapping styles in site.overrides so both .rich-input-content and .wrap-overflowing-text also handle rendered MathJax (mjx-container and common inline MathJax elements) with normal wrapping.
3. Kept search/result titles compact by truncating them to 100 characters in RecordsResultsListItem.js, instead of letting malformed MathJax titles stretch the list view.

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