Bugffix & imporovments of MdtCondDbAlg
Addresses a number of problems in MdtCondDbAlg
Functional changes (bugfix):
- intersect input ranges to find the proper output range
- Use AtH_CHECK macro to abort on failure
Less-important changes:
- Turn MdtCondDbAlg into a const-correct, re-entrant algorithm
- remove superfluous virtual keyword
@cheidegg: Maybe other muon conditions algorithms suffer from the same shortcomings? They should be fixed in tehe same way.
Closes ATLASRECTS-5141.