Add support for sonar.token parameter

[costin-zaharia-sonarsource]

sonar.token parameter was introduced on SonarQube and is meant to replace sonar.login and sonar.password parameters. We need to add support for it.

"The properties 'sonar.login' and 'sonar.password' are deprecated. They will not be supported in the future. Please instead use the 'sonar.token' parameter."

Currently the scanner supports a limited set of parameters on the end step.

This setting is not valid in the "end" phase in this version of the C# plugin: sonar.token

[costin-zaharia-sonarsource]

Closing this for now. It turns out that there was a misunderstanding between SonarQube team and PM. This will be implemented at a later point.