Feature Request: Add pre-filled form options to link handler in Help Center

Feature Request Summary: 

Help Center {{ link }} handler, specifically for 'new-request' identifier, should support pre-filled ticket form options.

Description/Use Cases: 

Help Center admins who use the {{ link }} handler in their theme are not able to craft links to ticket forms where they may want to have some ticket fields pre-filled. As such, they need to add a fully formatted <a> tag, which is not as intuitive and is not cohesive if you need to mix/match.

Example:

{{#link 'new_request' ticket_form_id='12345' role="menuitem"}}Sample Form{{/link}}

versus:

<a role="menuitem" href="/hc/en-us/requests/new?ticket_form_id=12345&tf_67890123456789=prefilled_option_1">Sample Form</a>

Desired functionality:

{{#link 'new_request' ticket_form_id='12345&tf_67890123456789=prefilled_option_1' role="menuitem"}}Sample Form{{/link}}

Business impact of limitation or missing feature:

This is a nice-to-have; a workaround exists, it is just not as user-friendly when working in the theme code. To the end user, the links above, whether using {{ link }} or <a>, render the same.

Other necessary information or resources:

https://developer.zendesk.com/documentation/help_center/help-center-templates/helpers/#new_request-link