Outsourcing compression and uncompression functions for coral::Blob handling

This MR provides a new module CoralUtilities in the Database package. It contains one component blobaccess.h by which a number of functions to read and write data to and from coral::Blob objects. These functions replace copy-pasted versions in the MuonSpectrometer package, but are not constrained to the muon system and can be used everywhere wherever data must be written to or read from blobs.

Name and location of the new module follows from a discussion with @tsulaia Additional base64 encoding/decoding functionality is required and an external has been added to Control/CxxUtils after discussion with @sroe and @fwinkl