Resolve "Show number of pods deployed on Deploy Boards"

What does this MR do?

• Adds number of total instances (pods) deployed to deploy boards.
• Adds a tooltip over the completion percentage that reveals number of instances (pods) completed.

Before	After - Total Count	After - Completed Count in Tooltip

What are the relevant issue numbers?

#5906 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• EE specific content should be in the top level /ee folder
• For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?

Closes #5906 (closed)