[electrophysiology_browser] Factorize recording panel and improve typing

[MaximeBICMTL]

Upstream of some changes from my MEG/MEEGqc branch so that it does not diverge too much from main.

Summary

This PR mostly moves code around and converts untyped class unfactorized components into typed functional dedicated components:

• Extract top-level recording component from session view into a typed functional RecordingSection component.
• Extract file details into a typed functional DetailsPanel component.
• Convert DownloadPanel and SummaryPanel into a typed functional component.
• Convert Sidebar and SidebarContent into a single typed functional component (the CSS is still rather dubious though).
• Change UI to use titles sections rather than nested panels (which take a lot of space and are visually ugly IMO).

Link with other PRs

This PR touches files also touched by two other PR:

• [electrophysiology_browser] On-demand file download tarring #10481. The changes to the download component are included in this PR.
• [electrophysiology_browser] Fix conditional EEG display #9742. The changes are not included in this PR.

The conflicts are rather simple, I will rebase this PR as needed if/when those are merged in main.

Showcase

2026-07-02.17-39-54.mp4