Juju incorrectly sets the charm origin during charm switches

[Jack Shaw]

Replicated in juju 3.3 and 2.9

```
$ juju deploy ubuntu
Located charm "ubuntu" in charm-hub, revision 24
Deploying "ubuntu" from charm-hub charm "ubuntu", revision 24 in channel stable on focal
$ juju refresh ubuntu --switch ./ubuntu
Added local charm "ubuntu", revision 12, to the model

$ juju mongo
juju:PRIMARY> db.applications.find().pretty()
...
{
 "_id" : "e87c04ee-bffa-4f41-8f75-03379fe9d25d:ubuntu",
 "name" : "ubuntu",
 "model-uuid" : "e87c04ee-bffa-4f41-8f75-03379fe9d25d",
 "series" : "focal",
 "subordinate" : false,
 "charmurl" : "local:focal/ubuntu-12",
 "cs-channel" : "stable",
 "charm-origin" : {
  "source" : "local",
  "id" : "DksXQKAQTZfsUmBAGanZAhpoS4dpmXel",
  "hash" : "9b2877f7ebf04b348cf40ace32fdfc6d1cc0157dea7fd6740c4ba74e0e201e5b",
  "revision" : 24,
  "channel" : {
   "risk" : "stable"
  },
  "platform" : {
   "architecture" : "amd64",
   "os" : "ubuntu",
   "series" : "focal"
  }
 },
 "charmmodifiedversion" : 1,
 "forcecharm" : false,
 "life" : 0,
 "unitcount" : 1,
 "relationcount" : 0,
 "minunits" : 0,
 "txn-revno" : NumberLong(5),
 "metric-credentials" : BinData(0,""),
 "exposed" : false,
 "scale" : 0,
 "passwordhash" : "",
 "provisioning-state" : null,
 "txn-queue" : [
  "65291ff89dc55c1137a0eb17_b7251f98"
 ]
}
```

NOTE: the charm origin has been fixed to state the source is local, but the id, hash and channel are present (which is not valid for a local charm) and the revision is 24, despite the revision being changed to 12

The following I have only been able to replicate in 3.3. This does not happen in 2.9

The problems continue when we switch back to a charmhub charm
```
$ juju refresh ubuntu --switch postgresql
$ juju mongo
juju:PRIMARY> db.applications.find().pretty()
...
{
 "_id" : "1005126d-2370-41c8-8aef-629ba663f5db:ubuntu",
 "name" : "ubuntu",
 "model-uuid" : "1005126d-2370-41c8-8aef-629ba663f5db",
 "subordinate" : false,
 "charmurl" : "ch:amd64/jammy/postgresql-288",
 "charm-origin" : {
  "source" : "charm-hub",
  "type" : "charm",
  "id" : "DksXQKAQTZfsUmBAGanZAhpoS4dpmXel",
  "hash" : "9b2877f7ebf04b348cf40ace32fdfc6d1cc0157dea7fd6740c4ba74e0e201e5b",
  "revision" : 288,
  "channel" : {
   "track" : "14",
   "risk" : "stable"
  },
  "platform" : {
   "architecture" : "amd64",
   "os" : "ubuntu",
   "channel" : "22.04"
  }
 },
 "charmmodifiedversion" : 2,
 "forcecharm" : false,
 "life" : 0,
 "unitcount" : 1,
 "relationcount" : 2,
 "minunits" : 0,
 "txn-revno" : NumberLong(5),
 "metric-credentials" : BinData(0,""),
 "exposed" : false,
 "scale" : 0,
 "passwordhash" : "",
 "provisioning-state" : null
}
```

Notice how the channel, source, platform and revision have all correctly switched. But the id and hash have not changed

[Jack Shaw (jack-shaw)]

This has been mostly resolved, but not entirely

See:
https://github.com/juju/juju/pull/16796#issuecomment-1910010705