Update testIsolationSelectionTool executable

Hi,

The IsolationSelectionTool package contains a small executable (testIsolationSelectionTool) to run local tests of the Iso-WP selection on (D)xAODs. This hasn't been updated since many years and used some very old WPs in the example. I updated this script a bit to reflect the newer WP and to make it a bit more flexible for users (e.g. to select the WP and lepton-pt/eta via a config-file).