MVC2: Footer source and web ide links

Related: #3085 (closed) + navigation#174 (closed)

What's changing in this MR?

1. We are adding Source and Edit buttons back into the footer. This MR changes the logic to build the Edit link from a page's Entry ID and that entry's Space ID.
2. This is done through an emitter at the page level (living in a mixin), where the Space and Entry IDs are provided from the page's asyncData call
3. I am going through each page created from the CMS to add all of this. It's going to take a bit 😬

Note: the Edit page link will not render if a Contentful Entry URL prop is not received. The link will not show on pages that have not been converted (see BE MR) OR are created from a yml file.

Navigation MR related to these changes: navigation!291 (merged)

List of impacted pages

PAGE	REVIEW APP LINK
/analysts	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/analysts
/community	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/community
/company/team/board-of-directors	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/team/board-of-directors
/company/team/e-group	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/team/e-group
/company/all-remote	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/all-remote
/company/contact	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/contact
/company	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company
/company/preference-center	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/preference-center
/company/visiting	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/company/visiting
/customers	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/customers
/customers/all	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/customers/all
/customers/anwb	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/customers/anwb
/dedicated	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/dedicated
/diversity-inclusion-belonging	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/diversity-inclusion-belonging
/events/devsecops-world-tour/executive/_city	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/devsecops-world-tour/executive/dallas/
/events/devsecops-world-tour/_city	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/devsecops-world-tour/atlanta/
/events/devsecops-world-tour	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/devsecops-world-tour
/events/aws-reinforce	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/aws-reinforce
/events/aws-reinvent	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/aws-reinvent
/events/google-cloud-next	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/google-cloud-next
/events/	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/
/events/kubecon	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/kubecon
/events/rsa	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/events/rsa
/install/ce-or-ee	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/install/ce-or-ee
/partners/benefits	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/partners/benefits
/partners/technology-partners/_partner	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/partners/technology-partners/ibm/
/partners/technology-partners	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/partners/technology-partners
/pricing/feature-comparison	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/pricing/feature-comparison
/pricing/licensing-faq	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/pricing/licensing-faq
/privacy	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/privacy
/resources	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/resources
/software-faster	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/software-faster
/demo	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/demo
/enterprise	https://view-source-and-website-functionality-with-cms-mvc2.about.gitlab-review.app/enterprise