Replace collapse button with accordion-style chevron toggle

[dvdstelt]

Fixes #2888

The separate pill button is replaced with a rotating chevron icon inline with the section title, following the standard accordion pattern. The expand state uses the same visual affordance, keeping the interaction consistent and familiar.

Reviewer Checklist

• Components are broken down into sensible and maintainable sub-components.
• Styles are scoped to the component using it. If multiple components need to share CSS, then a .css file is created containing the shared CSS and imported into component scoped style sections.
• Naming is consistent with existing code, and adequately describes the component or function being introduced
• Only functions utilizing Vue state or lifecycle hooks are named as composables (i.e. starting with 'use');
• No module-level state is being introduced. If so, request the PR author to move the state to the corresponding Pinia store.

[dvdstelt]

I just selected a few random people that I know somewhat regularly work on ServicePulse

[PhilBastian]

Added Warwick since he worked on the TF that implemented this section to see if there was a reason the original collapse button was chosen (I didn't realise it could be collapsed before)

[PhilBastian]

I think the build error is due to formatting. Prettier extension is expected to be present