Add api for database hosts

[Boy132]

Adds the following new endpoints to the application api:

	Endpoint	Description
GET	/api/application/database-hosts	list all database hosts
GET	/api/application/database-hosts/{database_host}	view a specific database host
POST	/api/application/database-hosts	create a database host
PATCH	/api/application/database-hosts/{database_host}	update a specific database host
DELETE	/api/application/database-hosts/{database_host}	delete a specific database host

Also adds a node include parameter to the database host transformer.

[github-actions]

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