Initial fallback strategy impl; works :)
Use the FallbackExecutionStrategy class if the lookup config is an Array, otherwise just a single lookup by name
Test Configuration with fallback setup
Find the query string from the query object rather than providing via search method
Test the simple execution strategy; basic tests as we cannot inject the Lookup 'factory'... or havent at the moment
Basic tests of FallbackExecutionStrategy; wip- need to build on these