Fix compatibility with client-side feathers-memory

When working with feathers-memory on the client, there's a conflict with the user of the params.paginate attribute. It expected an object, when feathers-vuex has been using it as a boolean. This isn't an issue when working with an API server, but when using feathers-vuex and feathers-memory in a Storybook, for example, it breaks pagination. This update transparently alters the params passed to the service's find method so that it matches what feathers-memory expects.

if (params.paginate === true) {
  params.paginate = { default: true }
}