[V4] Prepare for CodeCarbon V4

[benoit-cty]

This issue is for listing all breaking changes to put in V4:

• Remove CO2 Signal (now it raises a warning. This was introduced in this PR)
• Return dict instead of only CO2 emissions
• Add a 20% energy consumption for the whole machine
• Remove the viz-legacy extra, see Better support for carbonboard #1014

Please note that V4 is not planned yet.