NetworkPkg: Add NETWORK_HTTP_ENABLE macro

NetworkPkg: Add NETWORK_HTTP_ENABLE macro

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2917

Add NETWORK_HTTP_ENABLE macro and separate HttpDxe
and HttpUtilitiesDxe drivers from
HTTP_NETWORK_HTTP_BOOT_ENABLE macro.

Current NETWORK_HTTP_BOOT_ENABLE macro is defined to enable HTTP
boot feature in POST, this macro is not only enabling HTTP Boot
related modules but also enabling other generic HTTP modules
such as HttpDxe, HttpUtilitiesDxe and DnsDxe.
These HTTP base drivers would not be only used by HTTP boot
when we introduce the use case of Redfish implementation over
HTTP to edk2.
We should have a dedicate macro to enable generic HTTP functions
on Network stack and additionally provide NETWORK_HTTP_BOOT_ENABLE
for HTTP boot functionality for the use case that platform doesn't
require HTTP boot.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Nickle Wang <nickle.wang@hpe.com>
Cc: Peter O'Hanley <peter.ohanley@hpe.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>