Improve panel & visualization responsiveness

What does this MR do and why?

This change improves the panel & visualization responsiveness as described in Cube Query Rendering - Improve panel responsive... (#385181 - closed).

• [Dashboard] Adds a minimal height to the dashboard panel cells
• [SingleState] Only display the decimal places if the value is truthy.
  • Resolves SingleStat visualizations should not display de... (#391711 - closed)
• [Panels] Truncate title text.
  • Resolves Panel titles should be truncated on small sizes (#391712 - closed)
• Update specs

Known issues

LineChart does not fill the container height. There is a follow-up issue to resolve this in Update chart visualization to fill the panel co... (#393355 - closed). It's split out so that the above changes are unblocked by a GitLab UI issue GlLineChart: Chart does not fill container heig... (gitlab-ui#2167 - closed).

Screenshots or screen recordings

Before	After
Screen_Recording_2023-02-28_at_13.58.56	Screen_Recording_2023-02-28_at_14.00.25

How to set up and validate locally

To test the product analytics dashboard items are shown, you will need to follow the instructions at https://gitlab.com/gitlab-org/gitlab/-/snippets/2474959 to enable Product Analytics on your GDK.

Then visit the projects shared dashboards listing e.g. http://gdk.test:3000/gitlab-org/gitlab-test/-/analytics/dashboards

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.