Deprecate BlockType#isInteractable (#11427)

While BlockType is still marked as internal, it mirrors the already
paper-deprecated method #isInteractable.

The commit marks said method as deprecated if/when BlockType becomes
experimental/non-internal.

patches/api/Fix-Spigot-annotation-mistakes.patch

@@ -713,6 +713,25 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    @Deprecated(forRemoval = true, since = "1.13")
      void setData(@NotNull MaterialData data);
  
+     /**
+diff --git a/src/main/java/org/bukkit/block/BlockType.java b/src/main/java/org/bukkit/block/BlockType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/block/BlockType.java
++++ b/src/main/java/org/bukkit/block/BlockType.java
+@@ -0,0 +0,0 @@ public interface BlockType extends Keyed, Translatable {
+      * state as well. This method will return true if there is at least one
+      * state in which additional interact handling is performed for the
+      * block type.
++     * 
++     * @deprecated This method is not comprehensive and does not accurately reflect what block types are
++     * interactable. Many "interactions" are defined on the item not block, and many are conditional on some other world state
++     * checks being true.
+      *
+      * @return true if this block type can be interacted with.
+      */
++    @Deprecated // Paper
+     boolean isInteractable();
+ 
      /**
 diff --git a/src/main/java/org/bukkit/block/BrushableBlock.java b/src/main/java/org/bukkit/block/BrushableBlock.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644