Summary:
Add a checkbox to the Tokens screen that will allow a user to apply a "meta" filter to whatever other filters they have to only see those tokens which are listed for sale.
Acceptance Criteria:
User should be able to:
  • Select "Listed for sale" to ONLY see the tokens which match their filters AND are listed for sale
  • Unselect "Listed for sale" to see ALL tokens which match their filter REGARDLESS of whether they are listed for sale or not