Add device search field for asset tag in UI

[hyudra]

NetBox version

v2.10.4

Python version

3.6

Steps to Reproduce

On GUI, there's no asset_tag for searching. But it working with API or put it on url field

Expected Behavior

It should have field to search same as inventory items

Observed Behavior

No fields for filter

[jeremystretch]

Probably makes sense to add this for racks as well.