net/mlx5e: CT: Re-use tuple modify headers for identical modify actions

After removing the tupleid register which changed per tuple,
tuple modify headers set the ct_state, zone, mark, and label registers.
For non-natted tuples going through the same tc rules path, their values
will be the same, and all their modify headers will be the same.

Re-use tuple modify header when possible, by adding each new modify
header to an hahstable, and looking up identical ones before creating
a new one.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>