Feature/tech 586 plp countdown timer

[88joonyc]

This pull request allows multiple countdown clocks to render on the product list page.

In order for this to work, an identifier prop is used in the countdown component that dynamically sets the ID for each countdown. For this example case, the identifier is set to product.title. see below:

{%- for block in section.blocks -%}
    {%- case block.type -%}
      {%- when 'countdown' -%}
        {% liquid
          if product.metafields.global.countdown
            render 'countdown-trellis', 
            data: block.settings, 
            date: product.metafields.global.countdown, 
            identifier: product.title
            type: 'block'
          endif
        %}
    {%- endcase -%}
  {%- endfor -%}