Add support for templating implicit records in a zone

[David-Tamrazov]

This PR adds support for injecting implicit records into a zone based on a template provided by the consumer. When building its record set, each Zone will now loop through every template in its config and, for each template, inject any records it creates based on criteria defined within the template itself.

This allows consumers to define their own criteria for:

• which records should be used for template record generation
• the format of the template record and what data should go into it
• what sort of existing record conflicts should prevent the template-generated record from being injected

[XaF]

I know you're currently working on adding tests. Here's a first batch of comments 😀