Merge branch '425048-add-visualization-designer-feature-flag' into 'master'

Add analytics visualization designer feature flag

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131634



Merged-by: Halil Coban <hcoban@gitlab.com>
Approved-by: Minahil Nichols <minahilnichols@gitlab.com>
Approved-by: Aakriti Gupta <agupta@gitlab.com>
Approved-by: Halil Coban <hcoban@gitlab.com>
Approved-by: Elwyn Benson <ebenson@gitlab.com>
Co-authored-by: Jiaan Louw <3468028-jiaan@users.noreply.gitlab.com>
Co-authored-by: Minahil Nichols <minahilnichols@gitlab.com>
Co-authored-by: Jiaan Louw <jlouw@gitlab.com>