[Key Vault] Revise administration models

[mccoyp]

Resolves #13575 and resolves #18992.

[mccoyp]

Small but important detail here: ODataV4Format expects the inner error to be labeled as innererror, but the error we get back labels it as inner_error and doesn't get applied to the resulting ODataV4Format object. Does it make sense to edit the label to be innererror, or would that be forcing a square peg into a round hole?

[chlowell]

ODataV4Format expects JSON deserialized to a dict but the Error class generated by autorest has already deserialized the JSON and Pythonified "innererror" to "inner_error". What do you get from error.as_dict()? Also, ODataV4Format.innererror should be a JSON dict as well--it's JSON dicts all the way down.

[mccoyp]

error.as_dict() gives the same dictionary as vars(dict) -- we're still left with an inner_error key 😕

[chlowell]

Can you use the key_transformer argument to rename it?

[mccoyp]

Okay nice, that does work with something like:

def my_key_transformer(key, attr_desc, value):
    if key == "inner_error":
        return ("innererror", value)
    return (key, value)

for errors with no inner error (error.inner_error = None) and errors with JSON dict inner errors (they get recursively renamed)

[mccoyp]

It looks like something like this would work as well:

error.as_dict(key_transformer=lambda k, _, v: ("innererror", v) if k == "inner_error" else (k, v))

[mccoyp]

Closing, since other changes that affect these are being done in #19099.