ENH: DIMAP SEN products are shifted after orthorectification

[remi-braun]

As described in #50, orthorectifying SEN products leads to shift.

Tested on PLD and PLD Neo.
This needs more investigations.

[remi-braun]

Current workaroud:
If you can orthorectify the stack elsewhere, just set the ortho stack path as described here:

Here, if you want to orthorectify or pansharpen your data manually, you can set your stack here.

prod.ortho_stack = "/path/to/ortho_stack.tif"

[remi-braun]

In the DIMAP user guide it is written:

RPC is a generalised analytic model independent of the sensor data handling by the most current software. Users needing the highest level of accuracy (estimation greater than 3rd degree polynomial, block adjustment...) should prefer the rigorous sensor model (Primary product).

The rigorous model is described in section C.2 Using the Physical Model for the Primary Products and seems rather complicated.
I don't think I will implement such method for products not usually used in CEMS rapid mapping.

➡️ However, a note about this must be added in the documentation (and VHR tutorial).

🚨 Anyone interested in implementing this is welcome (even a draft).