Rewrite the marker chart so that there's one canvas per line instead of one big canvas

Currently the marker chart is one big canvas handling scrolling and zooming, as well as the mouse and keyboard interactions to handle these actions.

Instead we should split it in one canvas per line.

Planned benefits:

* the marker names as well as the category sections would be done with HTML, instead of drawn in the canvas, which makes it possible to use CSS to control their styles and search (and scroll) using the browser's builtin page search capabilities.
* there would be a scrollbar
* it would be possible to implement more interesting behaviors such as folding sections

Care should be taken with performance, especially an intersection observer will be used. Also all the previously used and mentioned behaviors need to be retained.

Related issue: #884

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-564)