Externals Update, master branch (2021.01.15.)

Updated all projects to atlasexternals-2.0.95. The list of changes wrt. atlasexternals-2.0.94 is (atlasexternals@2.0.94...2.0.95):

• Made it possible to use FindGaudi.cmake with a hand-built version of Gaudi. This is necessary for providing a functional development environment for the setup discussed on https://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/PrivateGaudiBuild. (Pinging @fwinkl.)
• Made it possible to globally change the default timeout of atlas_add_test(...) tests. This is meant for ATLINFR-3925. (Pinging @aundrus.)

Neither of the updates should really affect the current configuration of the CI build.