Document Manager; folder name for Security Statement Items changed

The Document Manager folder name for Security Statement Items has been changed from SecurityStmtItem to SecurityItem for consistency (mainly to the Permission Keys relating to Security Statement Items).

The business layer method finDocumentManagerFunctions.GetDocumentManagerFolder can receive an 'itemType' parameter or either 'SecurityItem' or 'SecurityStmtItem' and either will generate a folder name of 'SecurityItem'.