PartDesign: Add new need active body dialog with option to choose body (#4949)

* [PD] Add new need active body dialog

Intended for use wherever an active body is needed but none exists. The dialog
contains a list with the bodies present in the document, with an extra option to
make a new body. Custom text can be provided if needed.

This commit also replaces the warnings used by "new sketch" and "primitive"
command with this new dialog.

Addresses issue #4288.

src/Mod/PartDesign/Gui/CommandPrimitive.cpp

@@ -41,6 +41,7 @@
 
 #include "Utils.h"
 #include "WorkflowManager.h"
+#include "DlgActiveBody.h"
 
 using namespace std;
 
@@ -85,12 +86,15 @@ void CmdPrimtiveCompAdditive::activated(int iMsg)
     PartDesign::Body *pcActiveBody = PartDesignGui::getBody( /* messageIfNot = */ false );
 
     auto shouldMakeBody( false );
-    if (pcActiveBody == nullptr) {
+    if (!pcActiveBody) {
         if ( doc->getObjectsOfType(PartDesign::Body::getClassTypeId()).empty() ) {
             shouldMakeBody = true;
         } else {
-            PartDesignGui::needActiveBodyError();
-            return;
+            PartDesignGui::DlgActiveBody dia(Gui::getMainWindow(), doc);
+            if (dia.exec() == QDialog::DialogCode::Accepted)
+                pcActiveBody = dia.getActiveBody();
+            if (!pcActiveBody)
+                return;
         }
     }
 
@@ -104,7 +108,7 @@ void CmdPrimtiveCompAdditive::activated(int iMsg)
         pcActiveBody = PartDesignGui::makeBody(doc);
     }
 
-    if (pcActiveBody == nullptr) {
+    if (!pcActiveBody) {
         return;
     }