feat: add solana address creation via WASM

Implement the initial wasm-solana package to support Solana address
generation using Rust compiled to WebAssembly. This is the first phase
of replacing JavaScript Solana dependencies (@solana/web3.js, tweetnacl)
with secure Rust implementations to mitigate npm supply chain attack risks.

Architecture follows wasm-utxo patterns:
- Two-layer Rust design: core logic (src/*.rs) + thin WASM wrappers (src/wasm/*.rs)
- TypeScript wrappers (js/*.ts) providing idiomatic camelCase APIs
- Comprehensive test suite with BitGoJS compatibility tests

Components added:
- Keypair: Ed25519 keypair generation from random or 32/64-byte secret keys
- Pubkey: Base58 encoding/decoding for Solana addresses
- Error handling using js_sys::Error for proper JS exceptions

Build tooling:
- Cargo.toml with wasm-bindgen, solana-client-wasm, ed25519-dalek
- Makefile matching wasm-utxo's wasm-pack workflow
- TypeScript configs for ESM and CJS output

Verified compatibility with BitGoJS sdk-coin-sol test vectors to ensure
byte-identical address derivation from the same secret keys.

Ticket: BTC-2927

Author: lcovar

package-lock.json

@@ -0,0 +1,10 @@
+target/
+node_modules/
+# we actually only track the .ts files
+dist/
+test/*.js
+test/*.d.ts
+js/*.js
+js/*.d.ts
+js/wasm
+.vscode

packages/wasm-solana/.gitignore

@@ -0,0 +1,5 @@
+{
+  "extensions": ["ts", "tsx", "js", "jsx"],
+  "spec": ["test/**/*.ts"],
+  "node-option": ["import=tsx/esm", "experimental-wasm-modules"]
+}

packages/wasm-solana/.mocharc.json

@@ -0,0 +1,5 @@
+dist/
+target/
+js/wasm/
+pkg/
+node_modules/