Events: display levels in colors with advertise-colors=true

What

This MR is a follow up on !16190 (merged) which makes the levels be displayed in color when the terminal/output supports it.

Why

To better discern log messages visually.

Manually testing the MR

Use this in main.ml of EVM node:

  let log_cfg =
    Tezos_base_unix.Logs_simple_config.create_cfg ~advertise_levels:true ()
  in
  let config = make_with_defaults ~verbosity ~log_cfg () in