[mlir][ODS] Automatically create `result_segment_sizes` in builder

When using multiple variadic results of differing sizes, using `AttrSizedResultSegments` is currently a requirement. Unlike `AttrSizedOperandSegments` however, it is not created within the default builders created by tablegen. Instead, one has to explicitly add `DenseI32ArrayAttr:$result_segments_sizes` as argument and then also explicitly specify all the sizes when using the builder from C++.

This patch fixes that redundancy, by making the builder generate the attribute in similar fashion as it already does for `AttrSizedOperandSegments`. The sizes required are simply gathered from the result type arguments of the builder.

Differential Revision: https://reviews.llvm.org/D132656