Deprecate fs_suite pytest marker

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Deprecate pytest cliobj marker

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Add description for long-running pytest marker

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)