Feedback issue: To-Do item UI

As part of !99548 (merged), a couple of visual changes were made to the UI of To-Do items:

• Uses smaller font-size for meta data (namespace, title, timestamp)
• Uses icon buttons for actions
• Introduces a consistent two-line layout
• Removes target type name
• Removes individual links to project or target
• Fixes feature that your own username is highlighted in yellow
• Decreases avatar size from 40px to 24px
• Moves state pills to badges

If you have any questions, concerns or ideas for improvement, please add them to a comment in this issue 🙂

Follow-up MRs created

• Move todo state to beginning (!106573 - merged)
• Move title for todo to beginning of line (!106673 - merged)
• Move done button for to-dos on small devices (!106678 - merged)
• Make todos where you are mentioned two lined (!106689 - merged)
• Simplifies the design for todo mentions behind ... (!108091 - merged)
• Improve contrast of secondary text in dark mode (!108184 - merged)