message: print a deprecation warning when trying to use Collection.count()
diff: @@ -246,6 +246,11 @@ export default class Collection extends ShellApiWithMongoClass {
  @serverVersions([ServerVersions.earliest, '4.0.0'])
  @apiVersions([])
  async count(query = {}, options: CountOptions = {}): Promise<number> {
  + printDeprecationWarning(
  + 'Collection.count() is deprecated. Use countDocuments or estimatedDocumentCount.',
  + this._mongo._internalState.context.print
  + );
  +
  this._emitCollectionApiCall(
  'count',
  { query, options }
  