Switch to gtm

[hcorson-dosch-usgs]

Changes made:

This PR replaces the UA and GA4 tags with the GTM tag. It also fixes a display issue associated w/ the new carousel - it was too wide, so a horizontal scroll bar was appearing at the end of the charts section:

The GTM container has been configured to point to the existing GA4 account.

Tags on existing page:

Tags on updated page (previewed from local host):

Testing:

Before making this pull request, I:

• [X] Cleaned the code the way Vue likes it - run 'npm run lint --fix'
• [ ] Made sure all tests run
• [ ] Ran WAVE plugin 508 compliance tool

I can confirm this has been checked on:

• [X] Chrome
• [ ] Safari
• [X] Edge
• [X] Firefox
• [ ] Samsung Internet
• [ ] Internet Explorer 11 (not supported, but still needs at least a working user redirect page)