Tracker: Allow draggable container icon on Root, Trash and Printers

Use new DraggableContainerIcon name when invalidating icon.

Create a ShouldHaveDraggableFolderIcon() method on BContainerWindow
to consolidate the gating logic to a method.

We alert if you try and copy, move or create link to any of these
directories, however you may drag the icon in some instances such as
to change the directory in a file panel or to open the directory up
in FileTypes. You may create a link to the printers directory.

Set the Printer icon on the printers directory.

Fixes #3385

Tracker: Disks menu in CountView

* Open Disks directory on click.
* Skip volumes with no capacity (e.g. system, config) from
  Root and Desktop menus (still shown in Home and volumes though).
* No Trash on volumes, add only to Desktop.
* Declare some variables outside loop.
* Rename originatingWindow to source.

Fixes #3549

Change-Id: I66318d2485a5a8405f5459c355a467f34e19ecc5
Reviewed-on: https://review.haiku-os.org/c/haiku/+/9499
Reviewed-by: John Scipione <[email protected]>
Tested-by: Commit checker robot <[email protected]>

headers/private/tracker/DirMenu.h

@@ -49,11 +49,11 @@ public:
 		const char* entryName = 0);
 	virtual ~BDirMenu();
 
-	void Populate(const BEntry* startDir, BWindow* originatingWindow,
+	void Populate(const BEntry* startDir, BWindow* source,
 		bool includeStartDir = false, bool select = false,
 		bool reverse = false, bool addShortcuts = false,
 		bool navMenuEntries = false);
-	void AddItemToDirMenu(const BEntry*, BWindow* originatingWindow,
+	void AddItemToDirMenu(const BEntry*, BWindow* source,
 		bool atEnd, bool addShortcuts, bool navMenuEntries = false);
 	void AddDisksIconToMenu(bool reverse = false);