Move PlacementLocation from project to PackageManager

PlacementLocation define which local path is used for storing packages.
It has nothing to do with project (it's not even used there),
and should be contained inside PackageManager, even if currently
quite a few details are leaking all over the place.

Author: Geod24

source/dub/packagemanager.d

@@ -27,6 +27,19 @@ import std.string;
 import std.zip;
 
 
+/// Indicates where a package has been or should be placed to.
+public enum PlacementLocation {
+	/// Packages retrieved with 'local' will be placed in the current folder
+	/// using the package name as destination.
+	local,
+	/// Packages with 'userWide' will be placed in a folder accessible by
+	/// all of the applications from the current user.
+	user,
+	/// Packages retrieved with 'systemWide' will be placed in a shared folder,
+	/// which can be accessed by all users of the system.
+	system,
+}
+
 /// The PackageManager can retrieve present packages and get / remove
 /// packages.
 class PackageManager {

source/dub/project.d

@@ -1294,19 +1294,8 @@ enum ListBuildSettingsFormat {
 	commandLineNul, /// NUL character separated list entries (unescaped, data lists separated by two NUL characters)
 }
 
-
-/// Indicates where a package has been or should be placed to.
-enum PlacementLocation {
-	/// Packages retrieved with 'local' will be placed in the current folder
-	/// using the package name as destination.
-	local,
-	/// Packages with 'userWide' will be placed in a folder accessible by
-	/// all of the applications from the current user.
-	user,
-	/// Packages retrieved with 'systemWide' will be placed in a shared folder,
-	/// which can be accessed by all users of the system.
-	system
-}
+deprecated("Use `dub.packagemanager : PlacementLocation` instead")
+public alias PlacementLocation = dub.packagemanager.PlacementLocation;
 
 void processVars(ref BuildSettings dst, in Project project, in Package pack,
 	BuildSettings settings, in GeneratorSettings gsettings, bool include_target_settings = false)