Move the capsule parser into //third_party/quiche/common.

Capsules are not specific to HTTP/3, thus they should live in the common code.

PiperOrigin-RevId: 502730881
diff --git a/build/source_list.gni b/build/source_list.gni
index 965802a..22a646d 100644
--- a/build/source_list.gni
+++ b/build/source_list.gni
@@ -20,6 +20,7 @@
     "src/quiche/balsa/noop_balsa_visitor.h",
     "src/quiche/balsa/simple_buffer.h",
     "src/quiche/balsa/standard_header_map.h",
+    "src/quiche/common/capsule.h",
     "src/quiche/common/masque/connect_udp_datagram_payload.h",
     "src/quiche/common/platform/api/quiche_bug_tracker.h",
     "src/quiche/common/platform/api/quiche_client_stats.h",
@@ -219,7 +220,6 @@
     "src/quiche/quic/core/frames/quic_streams_blocked_frame.h",
     "src/quiche/quic/core/frames/quic_window_update_frame.h",
     "src/quiche/quic/core/handshaker_delegate_interface.h",
-    "src/quiche/quic/core/http/capsule.h",
     "src/quiche/quic/core/http/http_constants.h",
     "src/quiche/quic/core/http/http_decoder.h",
     "src/quiche/quic/core/http/http_encoder.h",
@@ -409,6 +409,7 @@
     "src/quiche/balsa/http_validation_policy.cc",
     "src/quiche/balsa/simple_buffer.cc",
     "src/quiche/balsa/standard_header_map.cc",
+    "src/quiche/common/capsule.cc",
     "src/quiche/common/masque/connect_udp_datagram_payload.cc",
     "src/quiche/common/platform/api/quiche_hostname_utils.cc",
     "src/quiche/common/platform/api/quiche_mutex.cc",
@@ -564,7 +565,6 @@
     "src/quiche/quic/core/frames/quic_stream_frame.cc",
     "src/quiche/quic/core/frames/quic_streams_blocked_frame.cc",
     "src/quiche/quic/core/frames/quic_window_update_frame.cc",
-    "src/quiche/quic/core/http/capsule.cc",
     "src/quiche/quic/core/http/http_constants.cc",
     "src/quiche/quic/core/http/http_decoder.cc",
     "src/quiche/quic/core/http/http_encoder.cc",
@@ -1025,6 +1025,7 @@
     "src/quiche/balsa/header_properties_test.cc",
     "src/quiche/balsa/simple_buffer_test.cc",
     "src/quiche/binary_http/binary_http_message_test.cc",
+    "src/quiche/common/capsule_test.cc",
     "src/quiche/common/masque/connect_udp_datagram_payload_test.cc",
     "src/quiche/common/platform/api/quiche_file_utils_test.cc",
     "src/quiche/common/platform/api/quiche_hostname_utils_test.cc",
@@ -1154,7 +1155,6 @@
     "src/quiche/quic/core/crypto/web_transport_fingerprint_proof_verifier_test.cc",
     "src/quiche/quic/core/deterministic_connection_id_generator_test.cc",
     "src/quiche/quic/core/frames/quic_frames_test.cc",
-    "src/quiche/quic/core/http/capsule_test.cc",
     "src/quiche/quic/core/http/http_decoder_test.cc",
     "src/quiche/quic/core/http/http_encoder_test.cc",
     "src/quiche/quic/core/http/http_frames_test.cc",