Prepare light-client for multi-environment support

[jeluard]

Lodestar relies heavily on nodejs specifics (e.g. Buffer or native modules). This allows to provide good performance for client artifacts (e.g. beacon-node, validator).

The light-client package can be used independently in a number of alternative environment (e.g. browser, ReactNative). While such usage can be made to work it requires polyfilling and dark magic heavily tool dependent.

According to my tests, here is the current support of light-client for a number of well-known bundlers/platforms:

Platform	Status	Issue
webpack5	✅	works for light-client; doesn't support node:* syntax
docusaurus	❓
AWS Lambda	❓
vite/astro	❌	Buffer usage
parcel	❌	top-level-await (in bls)
bun	❌	napi issues with bls
ReactNative	❌	exports
CloudFlare workers	❌	wasm limitations

Make sure we document supported platforms.

Different options should be pursued to improve this:

• reducing lodestar libs inter-dependency (only rely on env safe libs)
• reduce external dependencies; they should follow those same principles
• reduce usage of node modules; follow principled patterns easing their polyfilling when are mandatory

Inter-packages dependencies

• do not depend on state-transition
• Reduce light-client dependency on api #6542
• extract cli specific from utils
• extract node specific from logger (e.g. winston related)

NodeJS modules

• document patterns detailing preferred usage per module

In general:

• reduce dependencies on nodejs modules, when possible:
  • use global [crypto](https://nodejs.org/api/webcrypto.html, available by default starting node20, 1)
  • replace events with mitt or tseep
• consider creating helper function abstracting away node modules usage (similarly to what uint8arrays does)

It makes it simpler for end users of no shim are required.

light-client directly or indirectly depends on the following NodeJS modules:

From@chainsafe/blst #6519

• crypto
• path

From bls-eth-wasm

• crypto chore: upgrade bls-eth-wasm bls#158

From @chainsafe/bls

• crypto chore: remove node dependency herumi/bls-eth-wasm#23, chore: upgrade node platforms bls#159

From eventsource

• url
• https
• http
• util

External dependencies

• use bls switchable pattern; alternatively create an isomorphic blst (with wasm port of supranational); drop bls dependency Improve implementation selection strategy bls#157

Weight analysis

See bundlejs

Heavy packages

• bls herumi
• js-yaml, from utils