Echarts GlColumnChart Demo

What does this MR do?

This MR illustrates a selection problem of bars in our GlColumnChart.

A clicked item gets highlighted only on the next click, say I select the first bar and then the second bar, it would highlight the first bar on the second click.

Besides, the tooltip we're using should have an x/y offset so it won't interfere with the click handler.

Route: /-/analytics/productivity_analytics

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column_chart_selection_issue

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance and testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team