Convert `#text` to an array if multiple elements with the same name exist

[ohadravid]

Fixes #201

[omerbenamram]

Does this make the test at https://github.com/omerbenamram/evtx/blob/master/tests/test_record_samples.rs#L212 pass?

Edit: it seems test_event_json_with_multiple_nodes_same_name_separate passes - but test_event_json_multiple_empty_data_nodes_not_ignored fails