fix(model-client): wrong encoding/decoding of spaces in JS

MODELIX-515

Author: slisson

model-client/src/commonTest/kotlin/org/modelix/model/SerializationUtilEscapeTest.kt

@@ -22,6 +22,16 @@ class SerializationUtilEscapeTest {
         assertEquals("", SerializationUtil.escape(""))
     }
 
+    @Test
+    fun escape_space() {
+        assertEquals("+", SerializationUtil.escape(" "))
+    }
+
+    @Test
+    fun unescape_space() {
+        assertEquals(" ", SerializationUtil.unescape("+"))
+    }
+
     @Test
     fun unescape_emptyString() {
         assertEquals("", SerializationUtil.unescape(""))

model-datastructure/src/jsMain/kotlin/org/modelix/model/persistent/SerializationUtil.kt

@@ -18,14 +18,16 @@ actual object SerializationUtil {
         if (value == null) {
             return NULL_ENCODING
         }
-        return encodeURIComponent(value).map { SPECIAL_ENCODING[it] ?: it.toString() }.joinToString(separator = "")
+        return encodeURIComponent(value).asSequence()
+            .joinToString(separator = "") { SPECIAL_ENCODING[it] ?: it.toString() }
+            .replace("%20", "+")
     }
 
     actual fun unescape(value: String?): String? {
         if (value == NULL_ENCODING) {
             return null
         }
-        return decodeURIComponent(value!!)
+        return decodeURIComponent(value!!.replace("+", " "))
     }
 
     actual fun longToHex(value: Long): String {