Add keyfile option to keepassxc cli import cmd (#5402)

Fixes #5311

Added the keyFile logic from the create command to the import command and moved the loadFileKey() function
to the Utils class since it is now used in both create & import classes.

src/cli/Utils.cpp

@@ -371,4 +371,37 @@ namespace Utils
         return result;
     }
 
+    /**
+     * Load a key file from disk. When the path specified does not exist a
+     * new file will be generated. No folders will be generated so the parent
+     * folder of the specified file needs to exist
+     *
+     * If the key file cannot be loaded or created the function will fail.
+     *
+     * @param path Path to the key file to be loaded
+     * @param fileKey Resulting fileKey
+     * @return true if the key file was loaded succesfully
+     */
+    bool loadFileKey(const QString& path, QSharedPointer<FileKey>& fileKey)
+    {
+        auto& err = Utils::STDERR;
+        QString error;
+        fileKey = QSharedPointer<FileKey>(new FileKey());
+
+        if (!QFileInfo::exists(path)) {
+            fileKey->create(path, &error);
+
+            if (!error.isEmpty()) {
+                err << QObject::tr("Creating KeyFile %1 failed: %2").arg(path, error) << endl;
+                return false;
+            }
+        }
+
+        if (!fileKey->load(path, &error)) {
+            err << QObject::tr("Loading KeyFile %1 failed: %2").arg(path, error) << endl;
+            return false;
+        }
+
+        return true;
+    }
 } // namespace Utils