[mlir][vector] Make `TransposeOpLowering` configurable (#73915)

Following the discussion here:

  * https://github.com/llvm/llvm-project/pull/72105

this patch makes the `TransposeOpLowering` configurable so that one can select
whether to favour `vector.shape_cast` over `vector.transpose`.

As per the discussion in #72105, using `vector.shape_cast` is very beneficial
and desirable when targeting `LLVM IR` (CPU lowering), but won't work when
targeting `SPIR-V` today (GPU lowering). Hence the need for a mechanism to be
able to disable/enable the pattern introduced in #72105. This patch proposes one
such mechanism.

While this should solve the problem that we are facing today, it's understood to
be a temporary workaround. It should be removed once support for lowering
`vector.shape_cast` to SPIR-V is added. Also, (once implemented) the following
proposal might make this workaround redundant:

  * https://discourse.llvm.org/t/improving-handling-of-unit-dimensions-in-the-vector-dialect/