When GStreamer pipeline graphs contain references to other pipeline dot files,
users should be able to navigate between related pipeline views by clicking
on these references. This enables exploring complex pipeline hierarchies
where one pipeline references sub-pipelines.
The implementation detects text elements containing pipeline-dot references,
styles them as web links, and handles click events to navigate to the
referenced pipeline while preserving existing text selection and drag
functionality for other elements.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9547>
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