refactor: drop civetweb dependency and implement healtz using cpp-httplib

Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>

cmake/modules/cpp-httplib.cmake

@@ -0,0 +1,32 @@
+#
+# Copyright (C) 2022 The Falco Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+#
+
+#
+# cpp-httplib (https://github.com/yhirose/cpp-httplib)
+#
+if(CPPHTTPLIB_INCLUDE)
+	# we already have cpp-httplib
+else()
+	set(CPPHTTPLIB_SRC "${PROJECT_BINARY_DIR}/cpp-httplib-prefix/src/cpp-httplib")
+	set(CPPHTTPLIB_INCLUDE "${CPPHTTPLIB_SRC}")
+
+	message(STATUS "Using bundled cpp-httplib in '${CPPHTTPLIB_SRC}'")
+
+	ExternalProject_Add(cpp-httplib
+		PREFIX "${PROJECT_BINARY_DIR}/cpp-httplib-prefix"
+		URL "https://github.com/yhirose/cpp-httplib/archive/refs/tags/v0.10.4.tar.gz"
+		URL_HASH "SHA256=7719ff9f309c807dd8a574048764836b6a12bcb7d6ae9e129e7e4289cfdb4bd4"
+		CONFIGURE_COMMAND ""
+		BUILD_COMMAND ""
+		INSTALL_COMMAND "")	
+endif()