[mlir][vector] Remove ExtractMap/InsertMap operations

As discussed on discourse: https://discourse.llvm.org/t/vector-vector-distribution-large-vector-to-small-vector/1983/22
removing insert_map/extract_map op as vector distribution now uses
warp_execute_on_lane_0 op.

Differential Revision: https://reviews.llvm.org/D134000