Pass along UTMs when doing a blog redirect

[caldav]

Done

• Updated the blog redirection logic to append URL params.

QA

• Go to https://ubuntu-com-13381.demos.haus/blog/chiselled-ubuntu-ga?utm_source=marketo&utm_medium=email&utm_campaign=newsletter-2023-48
• Ensure you are redirected to the Canonical blog
• Ensure UTMs from the original URL are still there

[webteam-app]

Demo starting at https://ubuntu-com-13381.demos.haus

[codecov]

Codecov Report

Merging #13381 (c590280) into main (2c11e4b) will not change coverage.
Report is 14 commits behind head on main.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13381   +/-   ##
=======================================
  Coverage   74.41%   74.41%           
=======================================
  Files         107      107           
  Lines        2838     2838           
  Branches      946      946           
=======================================
  Hits         2112     2112           
  Misses        702      702           
  Partials       24       24           

[caldav]

Somehow, this doesn't work in the demo, but it works locally...

[lorumic]

I confirm that it works locally for me as well. Not sure why it fails on the demo server though. Let's maybe wait for a second reviewer from sites, who might know which could be the reason.

[akbarkz]

if this variable is used only inside the if block below, can you declare it there?

[caldav]

@akbarkz done, good catch, thank you