Fix session name label language switch + add frontend screenshot

- Store raw session name in STATE.currentSessionRawName
- Re-render session-name-display in toggleLang() with current translation
- Add frontend.png screenshot to README
- Bump 1.22.15, SW cache v46->v47

tests/test_pcap_import.py

@@ -224,7 +224,7 @@ class TestImportEndpoint(unittest.TestCase):
 class TestVersion(unittest.TestCase):
     def test_package_version(self):
         from simtrace2_pysniff import __version__
-        self.assertEqual(__version__, '1.22.14')
+        self.assertEqual(__version__, '1.22.15')
 
     def test_status_includes_version(self):
         import os