Add onEntityCollide function when entity are above a block

[Dhaiven]

Introduction

PocketMine don't have function to detect if an entity are above a block.
So i add a function and fix the bug with magma block.
But there are other bug of this type (with top of cactus...), so i must to be fix in this pr or open an other pr to fix them ?

Relevant issues

Fix #2041

Changes

API changes

Add Block::onEntityCollide()

Follow-up

Tests

Add-Magma-Block-PMMP.mp4

[IvanCraft623]

This does not really check if there is a collision so if there is a slab between the magma block and the player, the player will be burned.

[Dhaiven]

This does not really check if there is a collision so if there is a slab between the magma block and the player, the player will be burned.

Thanks for the feedback, it's fixed

[IvanCraft623]

The current implementation only works for collsions on down side. An appropriate solution to the problem would be to detect when colliding with any face of the block, not just one.

[Dhaiven]

The current implementation only works for collsions on down side. An appropriate solution to the problem would be to detect when colliding with any face of the block, not just one.

Fixed

[nicholass003]

should this case add this?

$hasUpdate = true;

[Dhaiven]

May be but if i realy good understand, hasUpdate variable is set to true only if entity is update. However, in function onCollide, we are not sure that entity is update.
So, i don't realy sure

[ShockedPlot7560]

Look OK to me