add signMessage for solana extension

[hcote]

📦 Pull Request

[Provide a general summary of the pull request here.]

Adds support for signing arbitrary Uint8Array payloads using the user's Solana private key

✅ Fixed Issues

• [List any fixed issues here like: Fixes #XXXX]

🚨 Test instructions

[Describe any additional context required to test the PR/feature/bug fix.]

⚠️ Don't forget to add a semver label!

• patch: Bug Fix?
• minor: New Feature?
• major: Breaking Change?
• skip-release: It's unnecessary to publish this change.

[magiclabsFE]

🚀 PR was released in @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-ext/[email protected], @magic-sdk/[email protected], @magic-sdk/[email protected], @magic-sdk/[email protected], @magic-sdk/[email protected], @magic-sdk/[email protected], [email protected] 🚀