feat: wasm caching

[weboko]

As of now .wasm files are retrieved by using fetch API which relies on server response whether to cache it and how long.

js-rln/src/rln.ts

Line 36 in 7e8cb89

const response = await fetch(url);

js-rln/src/rln.ts

Line 42 in 7e8cb89

const response = await fetch(url);

Problem with it that on simple or misconfigured servers it has no Cache policy and thus getting fetched always.
To fix it we should find a way to enforce caching.

First approach is to leverage IndexDB and put bytes into browser's memory with time-to-live restriction.
Dynamic import won't work here as it works only with ES modules.
LocalStorage cannot be used because of memory limitation.

Objectives

• use IndexDB to save bytes of wasm;
• investigate alternative approaches;