[refactor] Java11: Use Files.read/writeString

Author: dizzzz

exist-core/src/main/java/org/exist/source/FileSource.java

@@ -103,7 +103,7 @@ public InputStream getInputStream() throws IOException {
     @Override
     public String getContent() throws IOException {
         checkEncoding();
-        return new String(Files.readAllBytes(path), encoding);
+        return Files.readString(path, encoding);
     }
 
     @Override

exist-core/src/main/java/org/exist/storage/NativeBroker.java

@@ -722,7 +722,7 @@ private XmldbURI prepend(final XmldbURI uri) {
                     .map(h -> h.resolve("etc").resolve(INIT_COLLECTION_CONFIG))
                     .orElse(Paths.get("etc").resolve(INIT_COLLECTION_CONFIG));
             if (Files.exists(fInitCollectionConfig)) {
-                return new String(Files.readAllBytes(fInitCollectionConfig), UTF_8);
+                return Files.readString(fInitCollectionConfig);
             }
 
             // 2) fallback to attempting to load from classpath