Implement new package search in ui-plugin-find-eresource

Purpose:

Move to more responsive package search rather than using `/erm/electronic` endpoint with filter for packages

User story statement(s):

As an ERM librarian 
I want to all package searches to be consistent and responsive
so that I can find packages effectively no matter the route I use to search

Scenarios:

1. Scenario:
   • Given the ui-plugin-find-eresource 
   • When the plugin is used to find packages
   • Then it should use the `/erm/packages` endpoint
2. Scenario:
   • Given ui-plugin-find-eresource 
   • When the plugin is used to find packages
   • Then filters should be provided for:
     • Status
     • Scope
     • Availability
     • Content type
3. Scenario:
   • Given ui-plugin-find-eresource 
   • When the plugin is used to find titles
   • Then search should work across
     • name
     • identifiers.identifier.value
     • alternateResourceNames.name
     • description
4. Scenario:
   • Given ui-plugin-find-eresource 
   • When the plugin is used to find titles
   • Then search limit to retrieving 25 results at a time