cleanup: Map test files according to structure in src

For example cmd_account() is located in src/command/cmd_funcs.c.
The unit test was located in tests/unittests/test_cmd_account.c.
Let's move it to a subdirectory like tests/unittests/command/test_cmd_account.c
to correpsond to the same structure.

tests/unittests/config/test_preferences.c

@@ -0,0 +1,36 @@
+#include "prof_cmocka.h"
+#include <stdlib.h>
+#include <string.h>
+#include <glib.h>
+
+#include "config/preferences.h"
+
+void
+statuses_console_defaults_to_all(void** state)
+{
+    gchar* setting = prefs_get_string(PREF_STATUSES_CONSOLE);
+
+    assert_non_null(setting);
+    assert_string_equal("all", setting);
+    g_free(setting);
+}
+
+void
+statuses_chat_defaults_to_all(void** state)
+{
+    gchar* setting = prefs_get_string(PREF_STATUSES_CHAT);
+
+    assert_non_null(setting);
+    assert_string_equal("none", setting);
+    g_free(setting);
+}
+
+void
+statuses_muc_defaults_to_all(void** state)
+{
+    gchar* setting = prefs_get_string(PREF_STATUSES_MUC);
+
+    assert_non_null(setting);
+    assert_string_equal("none", setting);
+    g_free(setting);
+}

tests/unittests/config/test_preferences.h

@@ -0,0 +1,3 @@
+void statuses_console_defaults_to_all(void** state);
+void statuses_chat_defaults_to_all(void** state);
+void statuses_muc_defaults_to_all(void** state);