Using a bucket of water in creative mode will generate an empty bucket

[GH-PM]

Issue description

• Expected result: What were you expecting to happen? https://streamable.com/brpvoe
• Actual result: What actually happened? https://streamable.com/hiqx4b

Steps to reproduce the issue

1. Grab a bucket of water in creative mode
2. Use it anywhere
3. See how for every click you make with the cube, an empty cube is generated in your inventory

OS and versions

• PocketMine-MP: 5.0.0-BETA1
• PHP: 8.0.28
• Using JIT: not supported
• Server OS: linux
• Game version: Win10

Plugins

No plugins

• If you remove all plugins, does the issue still occur?
• If the issue is not reproducible without plugins:
  • Have you asked for help on our forums before creating an issue?
  • Can you provide sample, minimal reproducing code for the issue? If so, paste it in the bottom section

Crashdump, backtrace or other files

[dktapps]

This happens because of the following code: https://github.com/pmmp/PocketMine-MP/blob/b8f6b66e42e830539e5b24d532710d536bbdb8c2/src/player/Player.php#L1510

Unfortunately, the fix isn't as simple as adding a creative mode check, since we need to ensure that modified items (e.g. dyed/undyed shulker boxes) are returned properly here: https://github.com/pmmp/PocketMine-MP/blob/33140482bb66242c6ae6dc6e89fc0b61ea1ed930/src/block/WaterCauldron.php#L163

Ideally we would modify the $item directly for the shulker box case, but we're not currently able to do that, unless I make a BC break.

[dktapps]

This behaviour is quite a pain in the ass.

When used on a cauldron, buckets and bottles are both returned to the player empty. However, using a bucket on the ground doesn't have the same result. This behaviour is confusing and inconsistent, so I'm not sure what the correct behaviour should be.