Refactor: Anim: move struct bAnimListElem down in its header file

Move the `bAnimListElem` struct down in its header file, so that it sits
underneath the `enum` types that it uses. This move is necessary for an
upcoming refactor where the struct actually declares its fields to be of
those enum types.

Separating the move from the actual change in type will help with
clarity in the diffs.

No functional changes.

Pull Request: https://projects.blender.org/blender/blender/pulls/122874

source/blender/editors/include/ED_anim_api.hh

@@ -130,67 +130,6 @@ enum eAnimCont_Types {
 /** \name Channels
  * \{ */
 
-/**
- * This struct defines a structure used for quick and uniform access for
- * channels of animation data.
- */
-struct bAnimListElem {
-  bAnimListElem *next, *prev;
-
-  /** source data this elem represents */
-  void *data;
-  /** (eAnim_ChannelType) one of the ANIMTYPE_* values */
-  int type;
-  /** copy of elem's flags for quick access */
-  int flag;
-  /** for un-named data, the index of the data in its collection */
-  int index;
-
-  /** (eAnim_Update_Flags)  tag the element for updating */
-  char update;
-  /** tag the included data. Temporary always */
-  char tag;
-
-  /** (eAnim_KeyType) type of motion data to expect */
-  short datatype;
-  /** motion data - mostly F-Curves, but can be other types too */
-  void *key_data;
-
-  /**
-   * \note
-   * id here is the "IdAdtTemplate"-style datablock (e.g. Object, Material, Texture, NodeTree)
-   * from which evaluation of the RNA-paths takes place. It's used to figure out how deep
-   * channels should be nested (e.g. for Textures/NodeTrees) in the tree, and allows property
-   * lookups (e.g. for sliders and for inserting keyframes) to work. If we had instead used
-   * bAction or something similar, none of this would be possible: although it's trivial
-   * to use an IdAdtTemplate type to find the source action a channel (e.g. F-Curve) comes from
-   * (i.e. in the AnimEditors, it *must* be the active action, as only that can be edited),
-   * it's impossible to go the other way (i.e. one action may be used in multiple places).
-   */
-  /** ID block that channel is attached to */
-  ID *id;
-  /** source of the animation data attached to ID block */
-  AnimData *adt;
-
-  /**
-   * For list element which corresponds to a f-curve, this is an ID which
-   * owns the f-curve.
-   *
-   * For example, if the f-curve is coming from Action, this id will be set to
-   * action's ID. But if this is a f-curve which is a driver, then the owner
-   * is set to, for example, object.
-   *
-   * NOTE: this is different from id above. The id above will be set to
-   * an object if the f-curve is coming from action associated with that object.
-   */
-  ID *fcurve_owner_id;
-
-  /**
-   * for per-element F-Curves
-   * (e.g. NLA Control Curves), the element that this represents (e.g. NlaStrip) */
-  void *owner;
-};
-
 /**
  * Some types for easier type-testing
  *
@@ -297,6 +236,67 @@ enum eAnim_Update_Flags {
 #define ANIM_UPDATE_DEFAULT (ANIM_UPDATE_DEPS | ANIM_UPDATE_ORDER | ANIM_UPDATE_HANDLES)
 #define ANIM_UPDATE_DEFAULT_NOHANDLES (ANIM_UPDATE_DEFAULT & ~ANIM_UPDATE_HANDLES)
 
+/**
+ * This struct defines a structure used for quick and uniform access for
+ * channels of animation data.
+ */
+struct bAnimListElem {
+  bAnimListElem *next, *prev;
+
+  /** source data this elem represents */
+  void *data;
+  /** (eAnim_ChannelType) one of the ANIMTYPE_* values */
+  int type;
+  /** copy of elem's flags for quick access */
+  int flag;
+  /** for un-named data, the index of the data in its collection */
+  int index;
+
+  /** (eAnim_Update_Flags)  tag the element for updating */
+  char update;
+  /** tag the included data. Temporary always */
+  char tag;
+
+  /** (eAnim_KeyType) type of motion data to expect */
+  short datatype;
+  /** motion data - mostly F-Curves, but can be other types too */
+  void *key_data;
+
+  /**
+   * \note
+   * id here is the "IdAdtTemplate"-style datablock (e.g. Object, Material, Texture, NodeTree)
+   * from which evaluation of the RNA-paths takes place. It's used to figure out how deep
+   * channels should be nested (e.g. for Textures/NodeTrees) in the tree, and allows property
+   * lookups (e.g. for sliders and for inserting keyframes) to work. If we had instead used
+   * bAction or something similar, none of this would be possible: although it's trivial
+   * to use an IdAdtTemplate type to find the source action a channel (e.g. F-Curve) comes from
+   * (i.e. in the AnimEditors, it *must* be the active action, as only that can be edited),
+   * it's impossible to go the other way (i.e. one action may be used in multiple places).
+   */
+  /** ID block that channel is attached to */
+  ID *id;
+  /** source of the animation data attached to ID block */
+  AnimData *adt;
+
+  /**
+   * For list element which corresponds to a f-curve, this is an ID which
+   * owns the f-curve.
+   *
+   * For example, if the f-curve is coming from Action, this id will be set to
+   * action's ID. But if this is a f-curve which is a driver, then the owner
+   * is set to, for example, object.
+   *
+   * NOTE: this is different from id above. The id above will be set to
+   * an object if the f-curve is coming from action associated with that object.
+   */
+  ID *fcurve_owner_id;
+
+  /**
+   * for per-element F-Curves
+   * (e.g. NLA Control Curves), the element that this represents (e.g. NlaStrip) */
+  void *owner;
+};
+
 /** \} */
 
 /* -------------------------------------------------------------------- */