The existing `regex-path` debounce action can only concatenate capture groups, which cannot express some complicated URL transformations. This change adds a new `regex-path-template` debounce action type that constructs redirect URLs by substituting regex capture groups into a template URL specified by new field `redirect_url_template`. The URL template accepts $1..$9 placeholders for regex capture groups. This means we can have rules that allow URL transformations like `http://y2u.be/dQw4w9WgXcQ` => `https://www.youtube.com/watch?v=dQw4w9WgXcQ`