Added tls for http clients (#5766)

* Added global http client

* Added Do func for global http client

* Changed the code to use the global http client

* Fix http client in volume uploader

* Fixed pkg name

* Fixed http util funcs

* Fixed http client for bench_filer_upload

* Fixed http client for stress_filer_upload

* Fixed http client for filer_server_handlers_proxy

* Fixed http client for command_fs_merge_volumes

* Fixed http client for command_fs_merge_volumes and command_volume_fsck

* Fixed http client for s3api_server

* Added init global client for main funcs

* Rename global_client to client

* Changed:
- fixed NewHttpClient;
- added CheckIsHttpsClientEnabled func
- updated security.toml in scaffold

* Reduce the visibility of some functions in the util/http/client pkg

* Added the loadSecurityConfig function

* Use util.LoadSecurityConfiguration() in NewHttpClient func

weed/util/http/client/http_client_name_string.go

@@ -0,0 +1,23 @@
+// Code generated by "stringer -type=ClientName -output=http_client_name_string.go"; DO NOT EDIT.
+
+package client
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Client-0]
+}
+
+const _ClientName_name = "Client"
+
+var _ClientName_index = [...]uint8{0, 6}
+
+func (i ClientName) String() string {
+	if i < 0 || i >= ClientName(len(_ClientName_index)-1) {
+		return "ClientName(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _ClientName_name[_ClientName_index[i]:_ClientName_index[i+1]]
+}