Remove support for returnMeta query param

[pablopalacios]

returnMeta query param was introduced in order to handle a response format update from the server. There was a time that we would return the data from the resources without making any change. When returnMeta was introduced, we started formatting the response as following:

// successful responses:
{
    data: serviceResponseData,
    meta: serviceResponseMeta,
}

// error responses:
{
    output: serviceErrorOutput,
    meta: serviceResponseMeta,
}

returnMeta was then added to prevent outdated clients to break because of the new format. Years have passed and all browsers should have a fresh copy of fetchr by now. Therefore, we can remove the support for it as requested in the TODO comments (ex.

fetchr/libs/fetcher.client.js

Line 272 in 241a71c

// TODO: Remove `returnMeta` feature flag after next release

).

One caveat though: when the new format was added, we forgot to update the POST error responses. This PR also addresses this issue.

I confirm that this contribution is made under the terms of the license found in the root directory of this repository's source tree and that I have the authority necessary to make this contribution on behalf of its copyright owner.

[lingyan]

thanks for cleaning this TODO item up, @pablopalacios !
@redonkulus and I were talking about this recently, about why GET success case wasn't adding the meta data :)

@redonkulus, I checked our internal code using responseFormatter. this changes seems to be ok. You wanna double check?

[redonkulus]

We are already on v0.7.0 publicly, internally we are on fluxible-plugin-fetch@0.3.x which uses fetchr@0.5.x so this change will not affect us.

[pablopalacios]

@lingyan oh, but from what I see in the code, only the POST failed responses were not including the meta data. Unless you use a very old fetchr version, I think you should already have meta available. Could it be that the query parser or any other middleware is modifying the query object?

[redonkulus]

We are in fact on an old version of fetchr, we have not upgraded to the latest (as it requires regression testing across many apps).