Google analytics has outdated UTM parameters handler

[ihorml]

For anyone who is using / going to use GA4 plugin: https://github.com/DavidWells/analytics/blob/master/packages/analytics-plugin-google-analytics/src/browser.js#L284

This object should be replaced with the following (underscore instead of camelCase):

  if (id) campaign.campaign_id = id
  if (name) campaign.campaign_name = name
  if (source) campaign.campaign_source = source
  if (medium) campaign.campaign_medium = medium
  if (content) campaign.campaign_content = content
  if (keyword) campaign.campaign_keyword = keyword

[iloveitaly]

can you submit a PR for this?