Fix incorrect new blockdata in EntityChangeBlockEvent (#9445)

Also fixes EntityBreakDoorEvent not having the correct 'to' block data

Also standardizes how to handle EntityChangeBlockEvent before a removeBlock or destroyBlock
call. Always use 'state.getFluidState().createLegacyBlock()' to get the new state instead of
just using the 'air' state.

patches/api/0373-Collision-API.patch

@@ -0,0 +1,57 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
+Date: Wed, 6 Oct 2021 20:10:36 -0400
+Subject: [PATCH] Collision API
+
+
+diff --git a/src/main/java/org/bukkit/RegionAccessor.java b/src/main/java/org/bukkit/RegionAccessor.java
+index 8f50eb9b902236f5e039f5d26f3ca9a044b01a75..0d9184abd7090a5123a990f76847ee9b8971f735 100644
+--- a/src/main/java/org/bukkit/RegionAccessor.java
++++ b/src/main/java/org/bukkit/RegionAccessor.java
+@@ -469,5 +469,15 @@ public interface RegionAccessor extends Keyed { // Paper
+      * @return whether a line of sight exists between {@code from} and {@code to}
+      */
+     public boolean lineOfSightExists(@NotNull Location from, @NotNull Location to);
++
++    /**
++     * Checks if the world collides with the given boundingbox.
++     * This will check for any colliding hard entities (boats, shulkers) / worldborder / blocks.
++     * Does not load chunks that are within the bounding box.
++     *
++     * @param boundingBox the box to check collisions in
++     * @return collides or not
++     */
++    boolean hasCollisionsIn(@NotNull org.bukkit.util.BoundingBox boundingBox);
+     // Paper end
+ }
+diff --git a/src/main/java/org/bukkit/entity/Entity.java b/src/main/java/org/bukkit/entity/Entity.java
+index 97f0bc6573c8ba09de77061b6312b91cd713221d..3f3ea5bb6b3ea6f55b5cd699f1c01ac159619add 100644
+--- a/src/main/java/org/bukkit/entity/Entity.java
++++ b/src/main/java/org/bukkit/entity/Entity.java
+@@ -913,4 +913,26 @@ public interface Entity extends Metadatable, CommandSender, Nameable, Persistent
+      */
+     boolean isInPowderedSnow();
+     // Paper end
++
++    // Paper Start - Collision API
++    /**
++     * Checks for any collisions with the entity's bounding box at the provided location.
++     * This will check for any colliding entities (boats, shulkers) / worldborder / blocks.
++     * Does not load chunks that are within the bounding box at the specified location.
++     *
++     * @param location the location to check collisions in
++     * @return collides or not
++     */
++    boolean collidesAt(@NotNull Location location);
++
++    /**
++     * This checks using the given boundingbox as the entity's boundingbox if the entity would collide with anything.
++     * This will check for any colliding entities (boats, shulkers) / worldborder / blocks.
++     * Does not load chunks that are within the bounding box.
++     *
++     * @param boundingBox the box to check collisions in
++     * @return collides or not
++     */
++    boolean wouldCollideUsing(@NotNull BoundingBox boundingBox);
++    // Paper End - Collision API
+ }