Netbox: Toggle the display of available child prefixes

[snowie-swe]

Environment
NetBox version: 2.4.6

Proposed Functionality
Under Child prefixes add a toggle button to view available prefixes or not.
Default option in my opinion should be to have the available prefix hidden.

If you add a 10.0.0.0/8 as prefix you will automatically get several hundreds of available lines when viewing it under child prefixes that interfere with the user experience of the GUI.

Use Case
User friendliness

Database Changes

External Dependencies

[jeremystretch]

Please note that this change would require substantial work on the UI and likely won't be implemented for some time.

[snowie-swe]

Asked our devops to fix it in our dev env.
If its of interest i will ask them to upload the code changes needed.