"Monitor" Visibility Toggle

Problem to Solve

After #225307 (closed), #322790 (closed) and #246813 (closed) were implemented, the previous "Operations" menu became three separate top-level items ("Deployments", "Infrastructure" and "Monitor") in the left sidebar, as shown below.

We will need a separate visibility toggle for Monitor as seen in the Visibility, project features, and permissions settings. Currently, there is only one toggle for all of "Operations" when we need separate toggles for Deployments, Infrastructure, and Monitor.

Proposal

• Create a "Monitor" visibility setting in Settings > General > Visibility, project features, permissions
• When this setting is on users can see Alerts, Incidents, On Call Schedules, and Escalation Policies in the left hand navigation
• When this setting is off users can't see Alerts, Incidents, On Call Schedules, and Escalation Policies in the left hand navigation and these features aren't available.