feat: remote module security

[NathanWalker]

Security gating system for remote (HTTP/HTTPS) ES module loading in production.

• Enabled a new security section nativescript.config, enabling remote modules and specifying an allowlist of URL prefixes for permitted remote module sources.

In development, defaults to always enabled.
In production, only enabled via explicit developer approval in nativescript.config settings:

{
  "security": {
    "allowRemoteModules": true,   
    "remoteModuleAllowlist": [   // Optional: restrict to specific URL prefixes
      "https://cdn.example.com/modules/",
      "https://esm.sh/"
    ]
  }
}

If the optional remoteModuleAllowlist is omitted, it allows any url.

Docs added: https://github.com/NativeScript/docs/pull/191/files