Feat/refactor cloud instance

[da-ekchajzer]

This PR follows this discussion : #252

Improvements

• Externalizing impacts computation outside the asset's model by creating a service for this purpose (boaviztapi/service/impacts_computation.py)
• Updating cloud instance model and impacts computation in line with : Proposition to refactor cloud instance models and data #252 (comment)
• Improve impact mode (boaviztapi/model/impact.py)l. All the assets keep the impacts as an attribute once they have been calculated. Performance is significantly improved in the event of a verbose call (which would lead to impacts being recalculated).
• Fixed a bug I discovered by accident: power consumption was modelled for one component unit. Consumption was only multiplied by the number of components when calculating impacts at device level. The consumption of the component now reflects the consumption of all the units.

TODO

• Complete the file /data/archetypes/cloud/aws.csv with the new format done by @samuelrince
• Complete the /data/archetypes/server.csv file with the platforms mentioned in the aws.csv file done by @samuelrince
• Complete the /data/archetypes/server.csv file with finer-grained generic servers done by @samuelrince
• Rewriting tests for the cloud done by @da-ekchajzer
• ~~ Update cloud documentation~~ done by @da-ekchajzer see Doc : How to contribute to add new cloud instances, providers and CPU #250
• Create documentation on adding new instances (see Doc : How to contribute to add new cloud instances, providers and CPU #250) done by @da-ekchajzer see Doc : How to contribute to add new cloud instances, providers and CPU #250

[da-ekchajzer]

We have done all the item on the to-do list. I leave you sometime to review all the modifications.

[samuelrince]

I think we can merge this one :) @da-ekchajzer