progressively load icons

[AnxiousDarkly]

at the moment each time a category is selected, the entire icon set is loaded, which can be a lot of data, we should only really load chunks of a certain page size (say 80 icons).

• needs to be part of the build step (example & pkg)
• this can be achieved by using the rollup input property (instead of chunk analysis)

alternatively you could wrap each one in a dynamic import, there would be a ton of requests but it might make for a decent ux (i.e user can interact with icons the moment they are loaded).