* Move ASN to a separate module
* Move ASNField from dcim to ipam
* Introduce ASNRange model
* Add relationship from ASN to ASNRange
* Add an available-asns API endpoint
* Add RIR assignment for ASNRange
* Add standard tests
* Move child ASNs to a tabbed view
* Remove FK on ASN to ASNRange
* Add tests for provisioning available ASNs
* Add docs for ASNRange
* 10348 add decimal custom field
* 10348 fix tests
* 10348 add documentation
* Rearrange custom fields to be ordered consistently
* Rename number_field to integer_field for clarity
* Clean up validation logic
* Apply suggested changes from PR
* Store decimal custom field values natively
* Fix filter test
* Update custom field model migrations to use new encoder
Co-authored-by: jeremystretch <jstretch@ns1.com>
