feat: add observe api to js sdk

[G4Vi]

Resolves #68

• [x] Add span-enter, span-exit, metric, log, span-tags
• [x] Add dylibso_observe namespace imports mapping to the new functions
• [x] Add somewhat easier construction, with instantiateWasm
• [ ] Add new functions to adapters
  • [x] stdout
  • [ ] lightstep
  • [ ] datadog
  • [ ] honeycomb
• [x] Verify js sdk (not adapters) works on all platforms
  • [x] node
  • [x] web
  • [x] deno
  • [x] workerd?
• [x] Fix race condition with found in js/packages/observe-sdk-stdout/test/node/index.js with demangling