SUSHI behavior for fixed CodeableConcept may have unexpected results

SUSHI applies pattern values before processing rules (I think). As a result, in some cases (like CodeableConcept), it results in unexpected output if an instance rule overwrites a previously applied pattern value.

For example, given this profile and instance:
```
Profile: ConditionProfile
Parent: Condition
* code = http://foo.org|foov0.0.1#bar

Instance: MyCondition
InstanceOf: ConditionProfile
* code.coding[0] = http://notfoo.org#notbar
* code.coding[1] = http://foo.org|foov0.0.1#bar
* subject = Reference(Patient/John)
```
the instance ends up with the following code:
```json
{
"coding": [
{
"code": "notbar",
"system": "http://notfoo.org",
"version": "foov0.0.1"
},
{
"code": "bar",
"system": "http://foo.org",
"version": "foov0.0.1"
}
]
}
```
Note that the `http://notfoo.org#notbar` code ends up with the `foov0.0.1` system from the pattern.

Ideally, SUSHI should be smarter about how it does this so that it recognizes that `coding[0]` is assigned a different value that does not match the pattern -- and as a result, puts the pattern at `coding[1]` instead (ideally recognizing that although `coding[1]` also is also assigned a value, that value matches the pattern).

FSHOnline: https://fshschool.org/FSHOnline/#/share/3rfNkMb

Start by reproducing the ConditionProfile and MyCondition example from the issue, using the linked FSHOnline case if helpful, then trace SUSHI's pattern-value processing and instance-rule application. Done means an explicitly different coding[0] keeps its own system and version, while the matching pattern is placed on coding[1] without unexpected overwrites.

Written by the indexing model from the issue text.