SplitHTTP: More range options, change defaults, enforce maxUploadSize, fix querystring behavior (#3603)

* maxUploadSize and maxConcurrentUploads can now be ranges on the client
* maxUploadSize is now enforced on the server
* the default of maxUploadSize is 2MB on the server, and 1MB on the client
* the default of maxConcurrentUploads is 200 on the server, and 100 on the client
* ranges on the server are treated as a single number. if server is configured as `"1-2"`, server will enforce `2`
* querystrings in `path` are now handled correctly

transport/internet/splithttp/config_test.go

@@ -0,0 +1,51 @@
+package splithttp_test
+
+import (
+	"testing"
+
+	. "github.com/xtls/xray-core/transport/internet/splithttp"
+)
+
+func Test_GetNormalizedPath(t *testing.T) {
+	c := Config{
+		Path: "/?world",
+	}
+
+	path := c.GetNormalizedPath("hello", true)
+	if path != "/hello?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath2(t *testing.T) {
+	c := Config{
+		Path: "?world",
+	}
+
+	path := c.GetNormalizedPath("hello", true)
+	if path != "/hello?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath3(t *testing.T) {
+	c := Config{
+		Path: "hello?world",
+	}
+
+	path := c.GetNormalizedPath("", true)
+	if path != "/hello/?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath4(t *testing.T) {
+	c := Config{
+		Path: "hello?world",
+	}
+
+	path := c.GetNormalizedPath("", false)
+	if path != "/hello/" {
+		t.Error("Unexpected: ", path)
+	}
+}