Allow associating an export template with multiple object types

[jeremystretch]

NetBox version

v3.3.6

Feature type

Change to existing functionality

Proposed functionality

Change the content_type field on the ExportTemplate to a many-to-many relationship to ContentType, to enable associating an export template to multiple types. (This is essentially replicating #8274 for export templates instead of custom links.)

Use case

This change would allow the reuse of export templates across multiple object types.

Database changes

No response

External dependencies

No response