Marshaled nested wildcard field with `ordered=True` doesn't preserve dictionary key order.

[KungFuLucky7]

Marshaled nested wildcard field with ordered=True doesn't preserve dictionary key order.

Code

from flask_restx import fields, marshal

wild = fields.Wildcard(fields.String)
wildcard_fields = {'*': wild}
value = {'John': 12, 'bob': 42, 'Jane': '68'}
data = marshal(
      value, wildcard_fields, ordered=True
  )
print(data)

>> OrderedDict([('Jane', '68'), ('bob', '42'), ('John', '12')])

Repro Steps (if applicable)

1. See above sample code

Expected Behavior

The marshaled dictionary's keys have the same order.

OrderedDict([('John', '12'), ('bob', '42'), ('Jane', '68')])

Actual Behavior

The marshaled dictionary's keys order is not preserved.

Environment

• Python 3.9
• Flask version 1.1.2
• Flask-RESTX version 0.3.0
• Other installed Flask extensions

Additional Context

Currently I'm sorting the dictionary keys with a custom field to solve my problem:

class CustomNested(fields.Nested):
    def output(self, key, obj, ordered=True, **kwargs):
        data = super().output(key, obj, ordered=ordered, **kwargs)
        return OrderedDict(sorted(data.items()))

[KungFuLucky7]

Thank you!