huge refactor for high RewritePatterns usage and less ad-hoc cpp code

remove Spatial many ops in favor of tensor ops like in pim

src/PIM/Conversion/ONNXToSpatial/PrePatterns.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+#include "mlir/IR/MLIRContext.h"
+#include "mlir/Transforms/DialectConversion.h"
+
+namespace onnx_mlir {
+
+void populatePrePatterns(mlir::RewritePatternSet& patterns, mlir::MLIRContext* ctx);
+
+} // namespace onnx_mlir