Inconsistent field naming in data extension property settings

[wetneb]

In https://reconciliation-api.github.io/specs/draft/#data-extension-metadata, we have:

name
    A name for the setting, which identifies the setting uniquely;
label
    A human-readable label, which is used when presenting the setting to the user in a form;

This is confusing, because everywhere else we use id instead of name, and name instead of label.
We should switch to those for the sake of uniformity.