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_interface.go

@@ -0,0 +1,16 @@
+package client
+
+import (
+	"io"
+	"net/http"
+	"net/url"
+)
+
+type HTTPClientInterface interface {
+	Do(req *http.Request) (*http.Response, error)
+	Get(url string) (resp *http.Response, err error)
+	Post(url, contentType string, body io.Reader) (resp *http.Response, err error)
+	PostForm(url string, data url.Values) (resp *http.Response, err error)
+	Head(url string) (resp *http.Response, err error)
+	CloseIdleConnections()
+}