Review firefox utm paramters
From !1029 (comment 3031489).
In #42583 (closed) we modified moz-support-link
for base-browser, and also removed the utm
parameters that firefox sometimes adds to their support links.
We should review this decision, and also consider whether we also want to prevent utm
parameters in some other places: https://searchfox.org/mozilla-central/search?q=utm_content&path=&case=true®exp=false. E.g. they are sometimes added in "about:addons", like when you search for addons.
If we do want to remove the utm parameters for these other links, do we want them to be part of the moz-support-link commit?