Fix drag behavior being lost in compendiums & containers

In a few cases the drop handling was awaiting something before
fetching the drop behavior, causing the `_handleDragEnd` to be
called first which erases the stored drag behavior. Moving the
calls to `_dragBehavior` to the first thing in those drop methods
prevents this problem.

module/applications/item/container-sheet.mjs

@@ -152,8 +152,8 @@ export default class ContainerSheet extends ItemSheet5e {
    * @protected
    */
   async _onDropItem(event, data) {
-    const item = await Item.implementation.fromDropData(data);
     const behavior = this._dropBehavior(event, data);
+    const item = await Item.implementation.fromDropData(data);
     if ( !this.item.isOwner || !item || (behavior === "none") ) return false;
 
     // If item already exists in this container, just adjust its sorting

module/applications/item/item-compendium.mjs

@@ -55,8 +55,8 @@ class ItemCompendium5eV13 extends DragDropApplicationMixin(foundry.applications.
   /** @inheritDoc */
   async _handleDroppedEntry(target, data) {
     // Obtain the dropped Document
-    let item = await Item.fromDropData(data);
     const behavior = this._dropBehavior(event, data);
+    let item = await Item.fromDropData(data);
     if ( !item || (behavior === "none") ) return;
 
     // Create item and its contents if it doesn't already exist here
@@ -140,8 +140,8 @@ class ItemCompendium5eV12 extends DragDropApplicationMixin(
   /** @inheritDoc */
   async _handleDroppedEntry(target, data) {
     // Obtain the dropped Document
-    let item = await Item.fromDropData(data);
     const behavior = this._dropBehavior(event, data);
+    let item = await Item.fromDropData(data);
     if ( !item || (behavior === "none") ) return;
 
     // Create item and its contents if it doesn't already exist here

module/applications/mixins/drag-drop-mixin.mjs

@@ -21,7 +21,8 @@ export default function DragDropApplicationMixin(Base) {
     /* -------------------------------------------- */
 
     /**
-     * The behavior for the dropped data.
+     * The behavior for the dropped data. When called during the drop event, ensure this is called before awaiting
+     * anything or the drop behavior will be lost.
      * @param {DragEvent} event  The drag event.
      * @param {object} data      The drag payload.
      * @returns {DropEffectValue}