add bridge assets automatically to my markets list in search function

Bridge.xxx assets should be added automatically to the exchange pages search function, they are some of the most traded assets on the blockchain. When I create a bridge.btc tab it should automatically show its most traded pairs, users shouldn't have to add them all manually. In fact when any custom tab is created for an asset with a prefix, all other assets with the same prefix should automatically be added, allowing decent and useful lists to be easily created.

version 181212


Start by locating the exchange pages' search function and the code that creates custom asset tabs. Trace how manually added assets are stored and how asset prefixes are identified. Done means creating a prefixed custom tab automatically includes the other matching assets and their most-traded pairs in the search list.

Written by the indexing model from the issue text.