Fix Properties edge cases

[mfarragher]

After making some changes to integrate the logic from #51 into api.py, there are 4 tests that are failing and they seem to relate to these edge cases:

• Notes that have inline properties
• Notes that have whitespace in the property metadata

FAILED tests/test_api_property_wrangling.py::test_get_inline_properties - KeyError: 'due'
FAILED tests/test_api_property_wrangling.py::test_property_overriding - AssertionError: assert dict_keys(['prop1', 'prop2']) == dict_keys(['p...p2', 'prop3'])
FAILED tests/test_api_property_wrangling.py::test_property_special_chars - AssertionError: assert dict_keys(['p...with-quotes']) == dict_keys(['p...with-quotes'])
FAILED tests/test_api_property_wrangling.py::test_property_whitespace_handling - AssertionError: assert dict_keys([]) == dict_keys(['p...p4', 'prop5'])