Full WASM support

[ConorOkus]

Context

We want to finally make LDK Node run in WASM environments, in particular also as a Cloudflare worker.

Todo

• Refactor ldk-node core to be fully async; blocking APIs wrapped by an API layer that holds the runtime
  • Fully switch to async KVStore persistence #919
  • Make the API async where needed, avoid block_on  #926
• Make the runtime a trait, defaulting to tokio, with a WASM runtime as an alternative implementation
• Audit all uses of time; route them through a trait rather than std
• Audit all uses of tokio utilities; write context-agnostic replacements
• Introduce structured feature gates allowing opt-in to subsets of features; decide how to handle already-shipped features that aren't WASM-compatible (e.g. electrum)
• Make bitreq fully WASM-compatible, ship it, update downstream dependents (esplora-client, vss-client, etc.); wait for those releases before bumping in ldk-node
• Regression-test thoroughly — tokio has many idiosyncrasies we've debugged over the years, and the WASM runtime is reported to have its own

Related

#43

[heyolaniran]

hello @ConorOkus , can I work on this ?

[ConorOkus]

Hi @heyolaniran we have a few devs assigned to work on this already, but please do follow along and help us with reviewing the work if you have some time.