[Log Explorer] Enhance flyout customization extension point to support content replacement

[tonyghiani]

📓 Summary

In our ongoing effort to improve the Log Explorer, we need to enhance the existing flyout customization extension point.
Currently, this extension point allows for customizing the actions displayed on the flyout menu, but it lacks the ability to replace the entire content of the flyout, which is an essential requirement for implementing the newly proposed design.

✔️ Acceptance criteria

• Should be an incremental change and should keep the existing customization options.
• Should replace the flyout body with the passed function component.
• Should provide access to some internal details, such as the currently viewed document and the default flyout content.
• Should keep the pagination item to move between log entries.

💡 Implementation hints

This customization is made to allow consumers to customize the flyout content using the currently previewed document.
A possible API could be the following, where we provide the currently selected document and the previously existing content, in case the customization still wants to use it or move it around.

customizations.set({
  id: 'flyout',
  actions: {
    /* ... */
  },
  content: ({ doc, currentContent, onFilter }) => {
    return (
      <>
        <AgentInfo doc={doc} />
        {currentContent}
        <HostInfo doc={doc} />
      </>
    );
  },
});