Loading indicator improvements to audit search and filtering

[ngallegos]

When HTTP calls to ServiceControl take longer than expected, the audit messages view does not make it clear that the user is waiting for something to finish. This introduces some UI improvements to help with that:

• The message list now shows the loading spinner with an overlay when waiting on an HTTP call
• The refresh button is linked to HTTP calls instead of becoming ready after a hardcoded 1 second
• The search and filter controls become disabled along with the refresh button while data is being fetched

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.

[boblangley]

Tamara and I are going to push a commit for a new direction.

AuditList knows if a query is running. It should disable all of the form fields that can trigger a new query. We will abandon the 1 second refresh because now there is a loading spinner.

A future feature can add cancellation which is probably needed.