Add search to 'ConfigContext'

[bdlamprecht]

Environment

• Python version: 3.6
• NetBox version: 2.4.2

Proposed Functionality

Once again, great work with ConfigContext, it works perfectly!
Now, I'm wondering if it would be possible to add search functions to this extras Model?

Use Case

I've currently created only 15 objects here for DHCP, DNS, and it is already starting to get unwieldy:

With additional objects for syslog, snmp, tacacs, it is only going to get worse.

What I'm proposing is, at the very least, a search function similar to what was added in the Regions in #1366 (i.e. /dcim/regions/?q=).

Alternatively, something more full-featured like the options on Devices so you can filter on the name as well as on the assignments such as regions, sites, roles, etc.

Database Changes

I don't think any, but I could be wrong.

External Dependencies

None.