kpm - not setting plugin version should possible in PluginNamingResolver

[xsalefter]

If PluginNamingResolver created without specifying the pluginVersion, getPluginVersion() throw IllegalStateException. It is not correct, since we have a chances to analyzing version from stringContainsVersion.

IIRC, that assertion added when working with ArtifactAndVersionFinder, but as workaround, we can change that line in ArtifactAndVersionFinder with:

final String pluginNameAsArtifactId = pluginKey + "-plugin";

And then, we can remove PluginNamingResolver.of(pluginKey) static factory. And start to re-condider getPluginVersion() implementation. After all, none of operation in PluginNamingResolver should throw an exception, since even if we cannot found any version, it will return 0.0.0.