Concatenate on axis=1 with misaligned blocks
Allow to concatenate on axis 1 two tables made of misaligned blocks.
For example if the first table has 2 row blocks of 3 rows each, and the second table has 3 row blocks or 2 rows each.
To do that, I slice the row blocks to re-align the blocks.

Fix https://github.com/huggingface/datasets/issues/5413