fix(spans): Truncate long strings for fuse.js to prevent Firefox recursion

[sentry]

Fixes JAVASCRIPT-22SP: "InternalError: too much recursion" in Firefox.

This error occurred in waterfallModel.tsx when fuse.js attempted to build a search index for span data. fuse.js tokenizes strings using regex, and Firefox has a stricter regex call stack limit than other browsers. When span fields like indexed, tagKeys, tagValues, dataKeys, or dataValues contained excessively long strings (e.g., raw SQL queries, large JSON blobs, or base64 payloads), the regex operations would cause a stack overflow in Firefox.

The solution truncates these strings to a maximum length of 5000 characters before they are passed to fuse.js. This prevents the recursion error without affecting the actual display or integrity of the span data, as the truncation only applies to the search index.

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Fixes JAVASCRIPT-22SP

_{Comment @sentry <feedback> on this PR to have Autofix iterate on the changes.}