[FL-3918] Full-fledged JS SDK + npm packages

[portasynthinca3]

What's new

• Added npm packages: @flipperdevices/fz-sdk (contains the SDK, i.e. API typings and helper tooling), @flipperdevices/create-fz-app (interactive JS project creation wizard). These packages will be published manually by me if/when this pull request is merged.
• var and const keyword support in the interpreter
• Object.defineProperty stub
• JS API versioning system via sdkCompatibilityStatus, isSdkCompatible, assertSdkCompatibility. This might be not the right way. Please consider: JS: Backport³ and more additions & fixes #3961 (comment)

Verification

• Run unit tests
• Install Node.js together with npm
• Run the interactive project creation wizard:
  • If the packages do end up getting published, npx @flipperdevices/create-fz-app@latest
  • If not, cd js && npm exec ./create-fz-app. This will fail at the "Installing packages" step, which is expected if the package has not yet been published. Then, cd my-flip-app and change the version specifier in package.json for the fz-sdk package from ^0.1 to link:../fz-sdk
• cd into the newly created app
• Do npm start
• Verify that the app launches on the Flipper

Checklist (For Reviewer)

• PR has description of feature/bug or link to Confluence/Jira task
• Description contains actions to verify feature/bugfix
• I've built this code, uploaded it to the device and verified feature/bugfix

[github-actions]

Compiled f7 firmware for commit e24f9bcf:

• 📦 Update package
• 📥 DFU file
• ☁️ Web/App updater
• 📊 Size report

[portasynthinca3]

@hedger Please help me out with CI/CD here. Couple of things:

1. Docs generation for JS: cd applications/system/js_app/packages/fz-sdk && pnpm install && pnpm run build-docs will put the HTML into applications/system/js_app/packages/fz-sdk/docs.
2. Somehow link the main developer documentation with the new JS documentation
3. fbt really wants to format the images in applications/system/js_app/packages/fz-sdk/images. They're for displaying on the web, not for putting onto the device.