[MWRAPPER-148] Allow to use distributionVersion instead of distributionUrl in maven-wrapper.properties

**[Sebastian T](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=seb)** opened **[MWRAPPER-148](https://issues.apache.org/jira/browse/MWRAPPER-148?redirect=false)** and commented

It would be helpful if one could specify

```
distributionVersion=3.9.9
```

instead of

```
distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.9/apache-maven-3.9.9-bin.zip
```

in maven-wrapper.properties.

That would e.g. make programmatically upgrading the version in the file easier.

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**Affects:** 3.3.2