feat: Add Observe SDK support

[mhmd-azeez]

Fixes #21

[mhmd-azeez]

@nilslice @bhelx While the Go SDK supports instrument_enter, instrument_exit, and instrument_memory_grow, it doesn't seem to support span_enter and its friends. Should I implement them here, or should I open a PR in the observe-sdk repo?

[nilslice]

@nilslice @bhelx While the Go SDK supports instrument_enter, instrument_exit, and instrument_memory_grow, it doesn't seem to support span_enter and its friends. Should I implement them here, or should I open a PR in the observe-sdk repo?

Oh yea that's right. That would be a great PR on the observe-sdk repo!

[bhelx]

I can add those onto the Go SDK today. I think I already have a branch for it.

[bhelx]

What should we do with this PR? been on my review list for a long time

[nilslice]

In our meeting last week we decided to let it sit until things progress with migration to wasi-observe. But if we can use it in the meantime, I'd be all for updating to the latest API and merging with some experimental note.

The biggest change in-flux that would possibly impact this is the addition of a Context parameter to the instrumentation functions.

cc/ @chrisdickinson