Allow loading of LTM exports to the Viewer, although the memory servers have not been started

Steps if you want to test:

• Make some memory export and store it somewhere on the FS
• Kill all memories. Only start armem core scenario
• Open memory viewer GUI, disable drop of disconnected memories
• load the export

If a memory server is running -> the imported data will be commited to the server (as before) If no memory server is running -> create a new virtual memory (only available in GUI) and show data there