Bring Back Gamemode Selector for Commands in Bedrock Edition

In older versions of Minecraft Bedrock (before 1.17), it was possible to detect players in Creative Mode using commands such as: /testfor @a[m=1] or similar selectors. This feature was removed in newer versions, which makes it harder for map makers, command-block creators, and server owners to detect when a player switches to Creative Mode. Please consider adding a new selector or argument similar to Java Edition, for example: @a[gamemode=creative] so that we can use it in /execute, /testfor, and other commands. Bringing this back would help adventure maps, minigames, anti-cheat systems, and many creative community projects that rely on detecting gamemode changes. Thank you for considering this quality-of-life improvement for the Bedrock command system!