[VectorOps] Add vector ReshapeOp to the VectorOps dialect.

[VectorOps] Add vector ReshapeOp to the VectorOps dialect.

Adds vector ReshapeOp to the VectorOps dialect. An aggregate vector reshape operation, which aggregates multiple hardware vectors, can enable optimizations during decomposition (e.g. loading one input hardware vector and performing multiple rotate and scatter store operations to the vector output).

PiperOrigin-RevId: 286440658