fix(nuget): allow configurable versionScheme

Closes #4027

lib/manager/nuget/extract.js

-const { isVersion } = require('../../versioning/semver');
+const versioning = require('../../versioning');
 
 module.exports = {
   extractPackageFile,
 };
 
-function extractPackageFile(content) {
-  logger.debug('nuget.extractPackageFile()');
+function extractPackageFile(content, packageFile, config = {}) {
+  logger.trace(`nuget.extractPackageFile(${packageFile})`);
+  const { isVersion } = versioning.get(config.versionScheme || 'semver');
   const deps = [];
 
   let lineNumber = 0;