Feature Request: Set Notification Levels

[kevintraver]

Feature Request: Add config options to set notification levels for different events.

Could be set in config, maybe something like this:

notification_levels = {
    test = {
      not_found = "warn",
      error = "error",
      success = "info",
    },
    watcher = {
      start = "warn",
      stop = "info",
      not_found = "error",
    },
    lsp = {
      no_client = "warn",
    },
  }

and then lib.notify could use the config setting:

  lib.notify(("Stopping watch for %s"):format(position_id), config.notification_levels.watcher.stop)

Happy to help with PR.