Application.refresh() does not support passing new config options

[aieri]

Description

Reopening #981 as it was closed by the bot and I don't seem to be able to reopen it.

Urgency

It would save from a weird workaround

Code I'd Like to Run

await app.upgrade_charm(
    channel=channel,
    force_series=force_series,
    force_units=force_units,
    path=path,
    revision=revision,
    switch=switch,
    config=new_config_dict,
)