chore(restructure): reorganize project layout

- Reorganize internal packages and overall project structure
- Update imports and wiring to match the new layout
- Separate HTTP parsing and streaming from the server package
- Separate middleware from the server package
- Separate session registry from the session package
- Move HTTP, HTTPS, and TCP servers to the transport package
- Session package no longer starts the TCP server directly
- Server package no longer starts HTTP/HTTPS servers on initialization
- Forwarder no longer handles accepting TCP requests
- Move session details to the types package
- HTTP/HTTPS initialization is now the responsibility of main

internal/http/header/header.go

@@ -0,0 +1,30 @@
+package header
+
+type ResponseHeader interface {
+	Value(key string) string
+	Set(key string, value string)
+	Remove(key string)
+	Finalize() []byte
+}
+
+type responseHeader struct {
+	startLine []byte
+	headers   map[string]string
+}
+
+type RequestHeader interface {
+	Value(key string) string
+	Set(key string, value string)
+	Remove(key string)
+	Finalize() []byte
+	GetMethod() string
+	GetPath() string
+	GetVersion() string
+}
+type requestHeader struct {
+	method    string
+	path      string
+	version   string
+	startLine []byte
+	headers   map[string]string
+}