Refactor optical image metadata interface

See merge request orfeotoolbox/otb!765

Reading the metadata from the geom files without OSSIM

Closes #2106

See merge request orfeotoolbox/otb!759

Resolve SAR metadata interfaces

See merge request orfeotoolbox/otb!761

GEOM files are no longer générated as output, so we can't use them
to compare metadata on output files. Use directly the compare-metadata
function.

Compare image metadata in --compare-metadata

See merge request orfeotoolbox/otb!763

Deactivate PROJ's test building in the Superbuild

Closes #2113

See merge request orfeotoolbox/otb!764