Increase default grid and rename simple scene

Raise default Conway's Game of Life grid size from 40x40 to 50x50 (src/app/pages/algorithms/conway-gol/conway-gol.models.ts) to provide a larger initial viewport. Update i18n labels for the simple scene to 'Glider'/'Gleiter' in English and German respectively (src/assets/i18n/en.json, src/assets/i18n/de.json) for clearer naming.

src/assets/i18n/en.json

@@ -345,7 +345,7 @@
     "PAUSE": "Pause",
     "RANDOM_SCENE": "Random",
     "EMPTY_SCENE": "Empty",
-    "SIMPLE_SCENE": "Simple",
+    "SIMPLE_SCENE": "Glider",
     "PULSAR_SCENE": "Pulsar",
     "GUN_SCENE": "Gun",
     "ALIVE": "Alive",