Add metrics for distinct active workspace users

MR - Add metrics for distinct active workspace users (!192463 - merged)

Description

We would like to have metrics for daily, weekly and monthly active users.

We are discussing the definition of active users of workspaces here, will align with the decision soon.

It seems we already have a few events defined on our other issues, which could be used as input here,

• Event for clicking Open workspace button defined here, which could fit into opens a workspace
• Event for tracking workspace creation event defined here, which could fit into creates a workspace
• Event for tracking active workspace defined here, which could fit into workspace starts

We should utilize above events and data, and combine them into one single metric for active user. Also apply uniqueness on user_id to remove duplicated users from the count.

Acceptance criteria

• Add one service ping metrics for active users and use events/data defined from above list
• Ensure Tableau metric work as expected

Implementation plan

NA