#python iterator yields wrong message when topics is just a string and not a tuple

Iterator yields wrong message when topics is just a string and not a tuple. The issue occurs when the mcap file has to topics with the first charakters matching for example: ``` /sensors/1 /sensors/12 ``` the the iterator will always yield `/sensors/1` when you request `/sensors/12` the line of code that causes this issue is this one ``` if topics is not None and channel.topic not in topics: continue ``` in the seeking reader class in the iter messages function one possible fix is to call the function with a tuple `reader.iter_decoded_messages(topics=("/sensors/12",))` - Version:0.5.6 - Platform: Windows ``` from mcap_ros2.decoder import DecoderFactory from mcap.reader import make_reader file = "" reader = make_reader(file, decoder_factories=[DecoderFactory()]) reader.iter_decoded_messages(topics=("/sensors/12")) ``` **Expected Behavior** It should should yield /sensors/12 and not /sensors/1