Fail to update Maven packages with properties in their names

If a Maven dependency uses a property in its `artifactId` or `groupId`, the writer does not find the original definition of the package and will end up creating a new section for the patch.

e.g. Starting with this:
```xml

foo

com.xyz
${artifact}
1.0.0

```
A patch to `com.xyz:foo` will end up looking like:
```xml

foo

com.xyz
${artifact}
1.0.0

com.xyz
foo
2.0.0

```
Which, in this case, does not actually override the version of the package (despite the override claiming it would).