When running env import, add a default "objects" property to the package object

[jgoachermedable]

The mdctl env import command fails with the following error when run in the same directory as a package.json file which doesn't have an "object" property:

  object: 'fault',
  name: 'error',
  errCode: 'cortex.invalidArgument.unspecified',
  code: 'kInvalidArgument',
  message: 'Invalid Argument',
  status: 400,
  trace: undefined,
  path: undefined,
  resource: undefined,
  reason: 'The resource is missing the object property.',
  index: 0

The current workaround when this happens is to delete the package file.

This PR provides a fix by ensuring that an object loaded from a package.json file has an object property defaulted to the value package.

[jgoachermedable]

Note that the only effect of the new ImportSection call here is to map packageData to the new object's content property, so lines 104-105 could be replaced with just:

const { packageData: content, input, format } = privatesAccessor(this)

[jgoachermedable]

Closing, as mdctl should only be run within a folder with a package.json with an object property, e.g. see https://gitlab.medable.com/axon/org/-/blob/development/configuration/package.json