Remove duplicate CircleCI devops comparison pages

Why is this change being made?

This MR removes duplicate Circle CI devops comparison pages.

Page removed with this MR	URL it will redirect to with this MR
https://about.gitlab.com/devops-tools/circleci/CircleCI-BDM.html	https://devops-comparison-remove-duplicates-circleci.about.gitlab-review.app/devops-tools/circle-ci-vs-gitlab/bdm/
https://about.gitlab.com/devops-tools/circleci/CircleCI-License.html	https://devops-comparison-remove-duplicates-circleci.about.gitlab-review.app/devops-tools/circle-ci-vs-gitlab/license/
https://about.gitlab.com/devops-tools/circleci/GitLab-Over-CircleCI-Key-Differentiators.html	https://devops-comparison-remove-duplicates-circleci.about.gitlab-review.app/devops-tools/circle-ci-vs-gitlab/key-differentiators/

Removing duplicate content and pages is done for SEO.

This MR also moves one image from the /sites/marketing/source/devops-tools/circleci/ directory to /source/images/devops-tools/ directory. It also updates the paths these images in the final generated static HTML from /devops-tools/circleci/images/ to /images/devops-tools/

Moving images to a consistent directory is done for efficiency and in preparation for a webpack build process. Verify images are correctly linked in the review app here. Related https://gitlab.com/gitlab-com/marketing/growth-marketing/brand-and-digital/brand-and-digital/-/issues/354

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.