Add functionality for PSKT & PSKB

[smartgoo]

Mirror WASM32 SDK, providing support for PSKT and PSKB.

It looks like there are some PSKT/PSKB things missing (or at least open TODOs) in WASM SDK. Assess how to add here and then contribute back to rusty-kaspa to add features there.

[smartgoo]

This is WIP in #3

[smartgoo]

Pausing work on this (PR #3) as this is a niche feature and higher effort than anticipated. Will return to this in the hopefully near future once work on higher impact features is complete.

See update comment on PR #3 for more detail on current status, blockers and next steps.