[FEATURE] Support Binary Framing Layer for HTTP2

[gimlet2]

Feature Description

Implement the binary framing layer as defined by the HTTP2 protocol to replace the text-based HTTP/1.x message framing.

Problem/Use Case

A binary framing layer is essential for HTTP2's improved performance and flexibility. It allows structured frames for data and control signals.

Proposed Solution

• Parse and generate HTTP2 frames according to RFC 7540
• Support frame types: DATA, HEADERS, SETTINGS, PRIORITY, RST_STREAM, PUSH_PROMISE, PING, GOAWAY, WINDOW_UPDATE, CONTINUATION
• Ensure robust error handling for invalid frames

Code Example

val frame = Http2Frame(type = FrameType.DATA, payload = ...)
server.sendFrame(frame)

Alternatives Considered

• Retaining HTTP/1.x framing (not compliant)

Additional Context

• Would this be a breaking change? Yes
• Priority: High
• Related to HTTP2 support #3 HTTP2 support

Related Issues/PRs

• HTTP2 support #3 HTTP2 support