NetworkPkg: Add HTTP Additional Event Notifications

NetworkPkg: Add HTTP Additional Event Notifications

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3496

Add new EDKII_HTTP_CALLBACK_PROTOCOL in NetworkPkg,
Send HTTP Events via EDKII_HTTP_CALLBACK_PROTOCOL
when Dns/ConnectTcp/TlsConnectSession/InitSession
occurs.

Signed-off-by: Heng Luo <heng.luo@intel.com>
Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>