British vs. American spelling

[xoen]

Should we pick one and stick to it for consistency?

We now have a combination of the two:

• traits like Serialize, Deserialize, DeserializeOwned have American spelling
• attributes like serde_with::skip_serializing_none have American spelling
• some of our internal functions like normalise_dates() have British spelling...
• ...some like deserialize_power_data_test() have American spelling (although admittedly this is something I just introduced in this PR - we should probably)
• comments are also inconsistency

I don't think it hugely matter but it would be good to pick one and stick to it :)

FWIW IMHO maybe it would be best to stick to the American spelling given most of the 3rd party crates are bound to have the American spelling anyway. Although I appreciate the irony of this being a crate for the Carbon Intensity API for Great Britain 😬. Maybe this is a good argument for using the British spelling? (even tho inevitably we'd have a mixture of the two if we go this route).

[jnioche]

British, please! It is the GB carbon api ;-)