build: Allow building shared libraries

With this (default to OFF), commonly used and thus not prefixed with BASYX,
build option we can easily toggle to build shared libraries.

Compiled in release mode (CMAKE_BUILD_TYPE=Release) a resulting file size
difference (.a -> .so) can be shown:
(Size in bytes)
  185.276 -> 130.488   | libbasyx_aas
  485.494 -> 131.904   | libbasyx_abstraction
    5.016 ->  18.664   | libbasyx_log
    1.100 ->  16.960   | libbasyx_server
  425.100 -> 272.312   | libbasyx_shared
4.393.460 -> 939.904   | libbasyx_submodel
    1.092 ->  16.960   | libbasyx_util
1.822.564 -> 564.744   | libbasyx_vab
-----------------------+------------------
7.319.102 -> 2.091.936 | Sum

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