Make task counter bold to match related issues and MRs

What does this MR do and why?

• Makes task counter bold to match related issues and related MRs
• Uses gray-500 for all related item icons + counters

Screenshots or screen recordings

Before	After

How to set up and validate locally

Look at related items counters across issues/epics/MRs

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.