Use system include-style for STL and OpenSSL headers (#7066)

diff --git a/example/plugins/cpp-api/websocket/WSBuffer.cc b/example/plugins/cpp-api/websocket/WSBuffer.cc
index a53ac67..0bbd05d 100644
--- a/example/plugins/cpp-api/websocket/WSBuffer.cc
+++ b/example/plugins/cpp-api/websocket/WSBuffer.cc
@@ -25,7 +25,7 @@
 
 #include <ts/ts.h>
 #include "tscore/ink_config.h"
-#include "openssl/evp.h"
+#include <openssl/evp.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
diff --git a/include/tscore/Result.h b/include/tscore/Result.h
index fb99460..5436e42 100644
--- a/include/tscore/Result.h
+++ b/include/tscore/Result.h
@@ -25,13 +25,14 @@
 
 #include "TextBuffer.h"
 
+#include <utility>
+
 // Result is simple error object that carries a success/fail status and
 // a corresponding error message for the failure case. It is a simplified
 // form of Rust's Result object in that we don't carry a return value for
 // the success case. Arguably it ought to just be Error(), but Diags.h
 // already owns that name.
 
-#include <utility>
 struct Result {
   Result() {}
 
diff --git a/iocore/dns/P_SplitDNSProcessor.h b/iocore/dns/P_SplitDNSProcessor.h
index 6f42a47..e91923b 100644
--- a/iocore/dns/P_SplitDNSProcessor.h
+++ b/iocore/dns/P_SplitDNSProcessor.h
@@ -30,13 +30,6 @@
 
 #pragma once
 
-/*
-#include "P_DNS.h"
-#include "I_SplitDNS.h"
-#include "I_Lock.h"
-#include "ControlBase.h"
-#include "ControlMatcher.h"
-*/
 #include "ProxyConfig.h"
 
 /* ---------------------------
diff --git a/iocore/net/P_SSLSNI.h b/iocore/net/P_SSLSNI.h
index 6e83c2f..ff2dcc0 100644
--- a/iocore/net/P_SSLSNI.h
+++ b/iocore/net/P_SSLSNI.h
@@ -30,12 +30,12 @@
  ****************************************************************************/
 #pragma once
 
+#include <vector>
+#include <strings.h>
+
 #include "ProxyConfig.h"
 #include "P_SNIActionPerformer.h"
 #include "tscore/MatcherUtils.h"
-#include "openssl/ossl_typ.h"
-#include <vector>
-#include <strings.h>
 #include "YamlSNIConfig.h"
 
 // Properties for the next hop server
diff --git a/iocore/net/quic/QUICAltConnectionManager.cc b/iocore/net/quic/QUICAltConnectionManager.cc
index 3e95724..f1cb407 100644
--- a/iocore/net/quic/QUICAltConnectionManager.cc
+++ b/iocore/net/quic/QUICAltConnectionManager.cc
@@ -21,7 +21,8 @@
   limitations under the License.
  */
 
-#include "algorithm"
+#include <algorithm>
+
 #include "tscore/ink_assert.h"
 #include "tscore/ink_defs.h"
 #include "QUICAltConnectionManager.h"
diff --git a/iocore/net/quic/QUICPacketHeaderProtector_boringssl.cc b/iocore/net/quic/QUICPacketHeaderProtector_boringssl.cc
index 63e71bf..e27d206 100644
--- a/iocore/net/quic/QUICPacketHeaderProtector_boringssl.cc
+++ b/iocore/net/quic/QUICPacketHeaderProtector_boringssl.cc
@@ -23,7 +23,7 @@
 
 #include "QUICPacketHeaderProtector.h"
 
-#include "openssl/chacha.h"
+#include <openssl/chacha.h>
 
 bool
 QUICPacketHeaderProtector::_generate_mask(uint8_t *mask, const uint8_t *sample, const uint8_t *key, const EVP_CIPHER *cipher) const
diff --git a/iocore/net/quic/QUICTypes.h b/iocore/net/quic/QUICTypes.h
index a7fdc9f..c93de19 100644
--- a/iocore/net/quic/QUICTypes.h
+++ b/iocore/net/quic/QUICTypes.h
@@ -38,7 +38,7 @@
 #include <string>
 #include "tscore/ink_memory.h"
 #include "tscore/ink_inet.h"
-#include "openssl/evp.h"
+#include <openssl/evp.h>
 
 using QUICPacketNumber = uint64_t;
 using QUICVersion      = uint32_t;
diff --git a/proxy/ControlBase.h b/proxy/ControlBase.h
index 4c79d54..715b214 100644
--- a/proxy/ControlBase.h
+++ b/proxy/ControlBase.h
@@ -31,8 +31,9 @@
 
 #pragma once
 
+#include <vector>
+
 #include "tscore/ink_platform.h"
-#include "vector"
 
 class HttpRequestData;
 class Tokenizer;
diff --git a/proxy/http/HttpConfig.h b/proxy/http/HttpConfig.h
index f4f146b..06e1ccb 100644
--- a/proxy/http/HttpConfig.h
+++ b/proxy/http/HttpConfig.h
@@ -37,17 +37,14 @@
 #include <cstdio>
 #include <bitset>
 #include <map>
-
-#ifdef HAVE_CTYPE_H
 #include <cctype>
-#endif
+#include <string_view>
 
 #include "tscore/ink_platform.h"
 #include "tscore/ink_inet.h"
 #include "tscore/ink_resolver.h"
 #include "tscore/IpMap.h"
 #include "tscore/Regex.h"
-#include "string_view"
 #include "tscore/BufferWriter.h"
 #include "HttpProxyAPIEnums.h"
 #include "ProxyConfig.h"