TAChart: Add TParametricCurveSeries

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40137 4005530d-fff6-0310-9dd1-cebe43e6787f
TAChart: Add "Parametric" page to the "func" demo

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40138 4005530d-fff6-0310-9dd1-cebe43e6787f