Battery model refinement

[florentLutz]

This PR aims to work on refining the battery model, with main change being a switch from a pouch-cell based model to a cylindrical cell based model. Main reason is that it is what is used on the Velis Electro (Samsung 18650-....) and what may be used on the X57

The steps to finish this PR are:

• [x] Rework the OCV = f(SOC) model with the new cell (no dependency on T, see paper on X57 battery)
• [x] Rework the R_int = f(SOC, T) model. Adding a dependency on cell temperature ! See the added file in the methodology section for the justification
• [x] Rework the entropic heat coefficient model with Chiara's reference
• [x] Add an apparent battery capacity as suggested by A. Isikveren paper data can be obtained from cell datasheet.
• [x] Implement a proper reference cell (volume, weight and capacity as options as for the IGBT modules)
• [x] Add a battery efficiency computation module

And the usual suspects:

• [x] Components test
• [x] Assembly test
• [x] Mission vector test
• [x] See Impact on aircraft sizing in Notebooks