Only allow overwrites for pre release packages

[GuidoLeibbrand]

Problem

Currently, there is only the setting "AllowPackageOverwrites" in which you can generally set whether a package can be overwritten.

However, there is no option to allow overwriting only for pre-released packages.
In our environment, we also create SNAPSHOT versions.
For example: 1.1.0-SNAPSHOT.
The SNAPSHOT version can be built as often as you like and contains the latest git version for the Version.

Solution

In addition to the option AllowPackageOverwrites we need the option AllowPreReleasePackageOverwrites.
So we can explicitly control if a "pre release" package may be overwritten or not.