refactor(serif): updated tests to reflect new serif namespaces

tests/meson.build

@@ -4,7 +4,6 @@ gtest_main = dependency('gtest_main', required: true)
 gtest_nomain_dep = dependency('gtest', main: false, required : true)
 
 # Subdirectories for unit and integration tests
-subdir('dobj')
 subdir('const')
 subdir('meshIO')
 subdir('probe')
@@ -16,6 +15,5 @@ subdir('composition')
 subdir('poly')
 
 # Subdirectories for sandbox tests
-subdir('dobj_sandbox')
 subdir('composition_sandbox')