Cache search blocks and increase search debounce time (#1242)
Cache search blocks and increase search debounce time (#1242)

* Cache search blocks and increase search debounce time

* Make the search field select on focus and clear search cache

playi/pxt,Microsoft/pxt,switchinnovations/pxt,Microsoft/pxt,playi/pxt,playi/pxt,switch-education/pxt,switchinnovations/pxt,switch-education/pxt,switch-education/pxt,Microsoft/pxt,playi/pxt,Microsoft/pxt,switchinnovations/pxt,Microsoft/pxt,switch-education/pxt,switch-education/pxt,switchinnovations/pxt