Fixes the gap and size of CRUD components used in Work Items

What does this MR do and why?

Adjusts margins between various CRUD components within Work Item detail view, and unifies card header heights. While this MR modifies app/assets/javascripts/vue_shared/components/crud_component.vue, it ensures that changes are limited to Work Items only and do not affect other usages of crud_component.vue.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Go to a work item
2. Attach designs
3. Optionally enable feature flags workplan and workplan_decision_log to see Decision Log widget, which makes these visual inconsistency more prominent

MR acceptance checklist

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