Improve lua configuration and test files

Change lua test files to call `require 'lldebugger'` only when using
love, because it's not needed with lua or luajit. Also add `stopOnEntry`
key to test `.vimspector.json` because it works correctly with this
change.

support/test/lua/love-headless/.vimspector.json

@@ -10,7 +10,8 @@
         "program": {
           "command": "love"
         },
-        "args": ["${workspaceFolder}"]
+        "args": ["${workspaceFolder}"],
+        "stopOnEntry": false
       }
     }
   }