PCI Engagement Boost: Improve Manage page

[acicovic]

Is your request related to a problem?

The Manage Engagement Boost page is in need of a few improvements to make it snappier and easier to use.

Describe the solution you'd like

• [ ] 1. Add a spinner to the Views column, making the page accessible even if the underlying stats API is down or unresponsive.
• [ ] 2. Improve paging. The current paging has some quirks, including accepting an empty value which results in an error. Paging should be tested and reiterated to offer an improved experience.