value is in normal form.
The main reason to do this is to detect if a given chunk of
serialized data is in normal form: load the data into a
g_variant_new_from_data() and then use this function to check.
value is found to be in normal form then it will be marked as
being trusted. If the value was already marked as being trusted then
this function will immediately return
There may be implementation specific restrictions on deeply nested values. GVariant is guaranteed to handle nesting up to at least 64 levels.