Improved groups addressing and better diagnostics
While debugging TrigMinBiasMonitoringMT alg I discovered that the initialize is missed in the derived class implementation. The diagnostics was quite confusing and suggested that tool/group names are wrong. This MR improves the diagnostics and allows to use short & full GM tool names to be used in addressing.
To avoid this issue in the future it would be better to implement sysInitialize in the AthenaMonitoringAlg