-DBOOST_TEST_DYN_LINK is meant to be passed only to pulseview-test,
not to pulseview. When test were enabled, this flag was defined
globally, and as a result, also passed to pulseview.
Create a CMakeLists.txt for test, and add test as a subdirectory
when tests are enabled. This way, -DBOOST_TEST_DYN_LINK is only
defined for our test app.
Signed-off-by: Alexandru Gagniuc <redacted>