User dashboard changes for work items

What does this MR do and why?

User dashboard changes for work items

Changes:

• Backend: Add flag to HomepageData and SidebarsHelper
• Frontend: Dynamic labels in homepage widgets and sidebar
• Views: Conditional page titles in dashboard
• Icons: Update to 'work-items' icon consistently

When enabled, displays 'Work items' instead of 'Issues' in:

• Homepage assigned/authored widgets
• Sidebar issues counter
• Dashboard page title and heading
• 'Your Work' menu item

The icon changes from 'work-item-issue' to 'work-items' are applied unconditionally for visual consistency.

Changelog:added

References

Relates to #580272

Screenshots or screen recordings

With flag on	With flag off

How to set up and validate locally

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Related to #580272