[lit-analyzer] lit-analyzer uses non-standard JSON imports

[justinfagnani]

See https://github.com/runem/lit-analyzer/blob/master/packages/lit-analyzer/src/lib/analyze/data/get-built-in-html-collection.ts#L3

This prevents us from publishing standard JS modules and complicates Rollup builds.

We should move to fetch() and possibly top-level await, until standard JSON modules are available everywhere in the support matrix.