SearchKit - Process tokens in the "Add new" button

[colemanw]

Overview

Allows an "Add new" button on drilldown searches.

Before

SearchKit has an automatic "Add New" button for creating a new item. But it doesn't work with dynamic parameters, e.g. on the search of Custom Fields for a particular Custom Group (where custom_group_id is the param).

After

Feature added, and the "Administer Custom Fields" form switched from custom code to using the feature.

[civibot]

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[aydun]

All works ok.