Optimization of SLA print time estimation,

moved SLA print time estimation calculation into rasterization step,
so that the print time estimation is tracked by some SLAPrintStep.

Extended the output file name generator to use the SLA print statistics.

src/libslic3r/SLAPrint.hpp

@@ -2,7 +2,6 @@
 #define slic3r_SLAPrint_hpp_
 
 #include <mutex>
-#include "ClipperUtils.hpp"
 #include "PrintBase.hpp"
 #include "PrintExport.hpp"
 #include "Point.hpp"
@@ -237,8 +236,7 @@ public:
     }
     const PrintObjects& objects() const { return m_objects; }
 
-	std::string         output_filename() const override 
-        { return this->PrintBase::output_filename(m_print_config.output_filename_format.value, "zip"); }
+	std::string         output_filename() const override;
 
     const SLAPrintStatistics&      print_statistics() const { return m_print_statistics; }