Using fast-proxy-lite as default proxy library

Changes:

• The fast-proxy-lite module is used by default to support http proxy type 🔥. This means, no undici or http2 are supported by default.
• The old fast-proxy module is available under the http-legacy proxy type, but the module is not installed by default.
• Proxy configuration is now generalized under the proxyConfig property.
• Introduced "proxy factory" approach that simplifies the integration with custom proxy libraries.