Design pattern: Consolidate 1280px and fluid page widths

Via https://gitlab.com/gitlab-org/design.gitlab.com/issues/47 we define three page width options for any GitLab application page.

• 990px (prefered)
• 1280px (data-heavy pages)
• full-width (fluid)

Via latest discussion in https://gitlab.com/gitlab-org/design.gitlab.com/issues/47#note_87114700, we figured we can simplify even further by getting rid of 1280px.

Let's determine which pages we previously defined to use our 1280px width can be further moved to 990px, or full-width instead.

Copy of ~45 pages supposed to stay with 1280px and full-width we should review attached.

990px

Page	Path	Width review	Status
Projects
Project/Details (with just issues enabled)	/	⚠ enlarge to 1280px

1280px

Page	Path	Width review	Status
Projects
Project/Activity	/activity
Project/Security Dashboard	/security/dashboard
Repository/Fork	/forks/new
Repository/Blame	/blame/*
Repository/Contributors	/graphs	⚠ reduce to 990px
Repository/Compare/*	/compare/*	❓
Repository/Charts	/graphs/*/charts	⚠ reduce to 990px
Issues/List	/issues
Issues/Labels	/labels
Issues/Service Desk	/service_desk
Issues/Milestones	/milestones
Issues/Milestones/New OR Edit	/milestones/[new OR {id}/edit]
Merge requests	/merge_requests
CI-CD/Pipelines (List and view)	/pipelines
CI-CD/Jobs	/jobs
CI-CD/Charts	/pipelines/charts
Operations/Environment	/environments
Settings/Integrations/Edit integration	/services/{id}/edit
Settings/Audit Events	/audit_events
Groups-specific
Overview/Details	/
Activity	/activity
Contribution Analytics	/analytics
Epics/List	/epics
Settings/Billing	/profile/billings
Dashboards
Search	/search/*
All dashboard lists	/dashboard/[projects OR groups OR activity OR milestones OR snippets OR issues OR merge_requests OR todos]/*
Projects/Import/(Second list mapping step for all importers)	/import/*/status
User
Profile page	/{username}
Settings/Billings	/profile/billings
Admin Area
Overview	/admin
Overview/Project	/admin/projects
Overview/Groups	/admin/groups
Overview/Jobs	/admin/jobs
Overview/Cohorts	/admin/cohorts
Monitoring/System Info	/admin/system_info
Monitoring/Background Jobs	/admin/background_jobs
Monitoring/Logs	/admin/logs
Monitoring/Audit Log	/admin/audit_logs
Abuse Reports	/admin/abuse_reports
License	/admin/license
Service Templates/List	/admin/application_settings/services
Labels/List	/admin/labels
Instance Statistics
Cohorts	/stats/cohorts?