Large bundle size

I managed to generate an analysis of the bundle, which currently weighs more than 6 MB.

• plotly.js is the main culprit, taking almost 50% of the bundle. This clearly needs to be replaced with a more lightweight library, or at least split into a separate bundle and loaded asynchronously on the page that requires it (with a dynamic import()). !379 (merged)
• Another data visualization library is present: react-vis. We could try to use a single library for everything.
• tinymce is not that tiny 🥁 and accounts for 10% of the bundle. We could split it into a separate bundle and load it asynchronously only when needed.
• @appbase/reactivesearch could also be loaded asynchronously since it's used only on the search page.
• I can see two bootstrap table libraries: react-bootstrap-table and react-bootstrap-table-next. The latter seems to be the lightest, the most used, the most recent, and the most feature-full. We should migrate to it completely. !395 (merged)
• There is a lot more potential for improvement: d3-voronoi (!?), react-modal (why not use Bootstrap's Modal everywhere?), etc. -- but the above should already make a decent dent.
  • Remove react-moment !403 (merged)