Adds a deserialize filter operator (#7511)

* feat: added deserialize operator, tests and documentation

* fix: correct typo in lingo file

* fix: remove test that fails on node but succeeds in browser due to different availability of DOM deserializer

core/modules/filters/deserialize.js

@@ -0,0 +1,39 @@
+/*\
+title: $:/core/modules/filters/deserialize.js
+type: application/javascript
+module-type: filteroperator
+Filter operator for deserializing string data into JSON representing tiddlers
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports["deserialize"] = function(source,operator,options) {
+	var results = [],
+		deserializer;
+	if(operator.operand) {
+		// Get the deserializer identified by the operand
+		deserializer = $tw.Wiki.tiddlerDeserializerModules[operator.operand];
+		if(deserializer) {
+			source(function(tiddler,title) {
+				var tiddlers;
+				try {
+					tiddlers = deserializer(title);
+				} catch(e) {
+					// Return an empty array if we could not extract any tiddlers
+					tiddlers = [];
+				}
+				results.push(JSON.stringify(tiddlers));
+			});
+		} else {
+			return [$tw.language.getString("Error/DeserializeOperator/UnknownDeserializer")];
+		}
+	} else {
+		return [$tw.language.getString("Error/DeserializeOperator/MissingOperand")];
+	}
+	return results;
+}
+
+})();