Don't open branch/marker edit dialogs at cursor pos

resolves #3714 and #2369

src/BizHawk.Client.EmuHawk/tools/TAStudio/BookmarksBranchesBox.cs

@@ -575,11 +575,6 @@ namespace BizHawk.Client.EmuHawk
 				InitialValue = branch.UserText
 			};
 
-			var point = Cursor.Position;
-			point.Offset(i.Width / -2, i.Height / -2);
-			i.StartPosition = FormStartPosition.Manual;
-			i.Location = point;
-
 			if (this.ShowDialogWithTempMute(i).IsOk())
 			{
 				branch.UserText = i.PromptText;

src/BizHawk.Client.EmuHawk/tools/TAStudio/MarkerControl.cs

@@ -175,11 +175,6 @@ namespace BizHawk.Client.EmuHawk
 						""
 				};
 
-				var point = Cursor.Position;
-				point.Offset(i.Width / -2, i.Height / -2);
-				i.StartPosition = FormStartPosition.Manual;
-				i.Location = point;
-
 				if (!this.ShowDialogWithTempMute(i).IsOk()) return;
 
 				UpdateTextColumnWidth();
@@ -210,7 +205,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
-		public void EditMarkerPopUp(TasMovieMarker marker, bool followCursor = false)
+		public void EditMarkerPopUp(TasMovieMarker marker)
 		{
 			var markerFrame = marker.Frame;
 			var i = new InputPrompt
@@ -224,14 +219,6 @@ namespace BizHawk.Client.EmuHawk
 					: ""
 			};
 
-			if (followCursor)
-			{
-				var point = Cursor.Position;
-				point.Offset(i.Width / -2, i.Height / -2);
-				i.StartPosition = FormStartPosition.Manual;
-				i.Location = point;
-			}
-
 			if (!this.ShowDialogWithTempMute(i).IsOk()) return;
 
 			marker.Message = i.PromptText;

src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.ListView.cs

@@ -903,7 +903,7 @@ namespace BizHawk.Client.EmuHawk
 
 					if (existingMarker != null)
 					{
-						MarkerControl.EditMarkerPopUp(existingMarker, true);
+						MarkerControl.EditMarkerPopUp(existingMarker);
 					}
 					else
 					{