feat: Arrows to navigate search results while in a document (supersedes #3676)

[panglesd]

Supersedes #3676 with a branch in c2c_ui to be able to run the CI and deploy a preview.

Copy-pasted first post, but there were some answers on the initial PR that I don't copy paste.

This is an attempt to fix #3612.

When relevant, list of documents are attached a search_query field, containing the query that got them, with bounds centered on them.

Then, when a document is displayed, we are able to get "previous" and "next" documents and generate arrow buttons. We can also generate a list of results "a search navigation box".

A screenshot:

Questions/warnings/things to improve:

• I will need some help with the visual design!
• When visiting a waypoint, we can click on an associated route and the "associated search" will be the one for all routes associated to this one. BUT: the routes are ordered alphabetically, which is not possible in search queries.
• Similarly, when visiting a waypoint and clicking on an associated route, the search query associated is for all activities. We could restrict it to the activity that was clicked.

Let me know what you think! In my opinion it is very useful to navigate a set of documents using arrows.