c++ sdk: Allow to use an external shared libfmt

On systems where libftm is already available as library, rebuilding it is
useless. Instead use the ready available libfmt.

To not introduce a regression in building the sdk, the new option
BASYX_BUILD_LIBFMT is set to "ON". Users can switch the option off if desired.

Signed-off-by: Tobias Klausmann <tobias.klausmann@lenze.com>
2 files changed