Update gnome-shell-extensions submodule + fix coding standard issues

Notes:
- gnome-shell-extensions default branch was renamed to "main"
- Fixed issues from new ESLint rules
- Fixed issues from review https://extensions.gnome.org/review/27899
- Removed compatibility with pre-v3.34 versions of GNOME Shell
  since initTranslations() and getSettings() are present
  in extensionUtils only since

.gitmodules

@@ -1,3 +1,4 @@
 [submodule "gnome-shell-extensions"]
 	path = gnome-shell-extensions
 	url = https://gitlab.gnome.org/GNOME/gnome-shell-extensions.git
+	branch = main

extension.js

@@ -19,14 +19,14 @@
 const History = imports.misc.history;
 
 const ExtensionUtils = imports.misc.extensionUtils;
-const Me = ExtensionUtils.getCurrentExtension();
-const Convenience = Me.imports.convenience;
-const Prefs = Me.imports.prefs;
 
 let historyManagerInjections = {};
 let settings;
 
+/** GNOME Shell Extension API */
 function enable() {
+    settings = ExtensionUtils.getSettings();
+
     historyManagerInjections['prevItemPrefix'] = undefined;
     historyManagerInjections['nextItemPrefix'] = undefined;
     historyManagerInjections['_onEntryKeyPress'] = undefined;
@@ -83,6 +83,11 @@ function enable() {
     });
 }
 
+/**
+ * @param {object} objectPrototype - object prototype to be modified
+ * @param {string} functionName - name of the function to be overriden
+ * @param {Function} injectedFunction - new function to be injected instead of @functionName
+ */
 function overrideFunction(objectPrototype, functionName, injectedFunction) {
     let originalFunction = objectPrototype[functionName];
 
@@ -98,6 +103,11 @@ function overrideFunction(objectPrototype, functionName, injectedFunction) {
     return originalFunction;
 }
 
+/**
+ * @param {object} objectPrototype - object prototype to be modified
+ * @param {string} functionName - name of the original function after which @injectedFunction will be executed
+ * @param {Function} injectedFunction - new function to be executed after @functionName
+ */
 function injectAfterFunction(objectPrototype, functionName, injectedFunction) {
     let originalFunction = objectPrototype[functionName];
 
@@ -117,23 +127,33 @@ function injectAfterFunction(objectPrototype, functionName, injectedFunction) {
     return originalFunction;
 }
 
+/**
+ * @param {object} objectPrototype - object prototype to be modified
+ * @param {Function} injection - original function to be returned to the @objectPrototype
+ * @param {Function} functionName - name of the function in the @objectPrototype
+ */
 function removeInjection(objectPrototype, injection, functionName) {
     if (injection[functionName] === undefined)
         delete objectPrototype[functionName];
     else
         objectPrototype[functionName] = injection[functionName];
 }
 
+/** GNOME Shell Extension API */
 function disable() {
     for (let i in historyManagerInjections)
         removeInjection(History.HistoryManager.prototype, historyManagerInjections, i);
+
+    settings = null;
 }
 
+/** GNOME Shell Extension API */
 function init() {
-    settings = Convenience.getSettings(Prefs.PREFS_SCHEMA);
 }
 
-// 3.0 API backward compatibility
+/**
+ * 3.0 API backward compatibility
+ */
 function main() {
     init();
     enable();

metadata.json

@@ -1,19 +1,6 @@
 {
     "shell-version": [
-        "3.6",
-        "3.7",
-        "3.7.3",
-        "3.8",
-        "3.10",
-        "3.12",
-        "3.14",
-        "3.16",
-        "3.18",
-        "3.20",
-        "3.22",
-        "3.24",
-        "3.26",
-        "3.28",
+        "3.34",
         "40",
         "41",
         "42",