JSONField not accepting string values

Describe the bug

JSONField should be a generic field that accepts anything that can be "stringfied" to json, and that string be loaded back to their original values.

Currently, trying to pass a string to JSONField makes it try to decode it first, which raises an error saying that the value is not a valid json value.

To Reproduce

Try to set any JSONField to any string, like "foobar"

Expected behavior

The expected behaviour would be that any serializable value would be JSON stringified and then be converted back. E.g, using the json module:

In [1]: import json

In [2]: json.dumps("foobar")
Out[2]: '"foobar"'

In [3]: json.loads('"foobar"')
Out[3]: 'foobar'

In [4]: json.dumps(123)
Out[4]: '123'

In [5]: json.loads('123')
Out[5]: 123

More specifically, if I set a string on it, I expect a string back. If I pass an int to it, I expect an int back. If I pass some dict to it, I expect that dict back, as long as the encoder/decoder can encode/decode those attributes.

This is also the way most JSONField works, like django's.

Start by locating the JSONField implementation and reproduce the issue by assigning a string such as "foobar". Check the field's serialization and deserialization path; done means strings, integers, and dictionaries round-trip to their original values when supported by the encoder and decoder.