[JENKINS-22073] ProjectAction should render graph, optimize build.xml size

- Issue: The trend graph is part of project/job page and should be created in CppcheckProjectAction instead of in CppcheckBuildAction.
- Issue: Every build.xml file contains full plugin configuration, this is not needed.
- Creating of the graph moved from CppcheckBuildAction to proper CppcheckProjectAction.
- CppcheckBuildAction now stores no configuration which results in smaller build.xml.
- Various methods updated to receive only CppcheckConfigSeverityEvaluation in their parameters.
- Weather column in the jobs table (mouse over tool tip) updated to contain only a constant label with a percentage, use of a deprecated API removed. It isn't neccessary to dynamically show a configuration here. This allows to replace whole <configSeverityEvaluation> part of build.xml by one integer.
- Several @SuppressWarnings("unused") that are causing compiler warnings removed.
- Code updated to be better readable.