Per-gene summary information should be cached

[pjvandehaar]

On https://bravo.sph.umich.edu/freeze8/hg38/gene/snv/TTN , the server takes 10 seconds to return the summaries at the top of the page, like the number of synonymous variants, frameshifts, etc. That information could be cached to be fast after the first load. If this issue isn't relevant for the new architecture, feel free to close it.