[Linalg] Add a Linalg iterator permutation transformation.

[nicolasvasilache]

Once #270 is landed, we can add a standalone iterator permutation transformation to Linalg.

This transformation should be very simple to write and should just compose a permutation map the with the maps in the "indexing_maps" attribute.

There is a C++ component and a Tablegen component (to make the transformation into a pattern) to this PR.

[tetuante]

Working on it!

[nicolasvasilache]

Done.