Fix topic filter matching

[lrasku]

• re.escape() the whole filter string first to escape all regex metacharacters in it, not just $. (# and + are both regex metacharacters, so their replace expressions now need a leading \ to replace the escaping, too.)
• # matches topics both with and without a trailing /, so the replace expressions adds a '?' before the '.*'. The .lstrip('?') at the end removes this in case the # was the first character in the filter.
• + should only match a single level, but it should also match empty levels, so use '[^/]*' to replace it.
• Use Regex.fullmatch() to match against the whole topic string, not just its start.

Also add two unit tests to test this matching, and fix an incorrect match against + in test_client_subscribe_publish_dollar_topic_2.

This fixes #44.

[FlorianLudwig]

Hi @lrasku

hbmqtt has been deprecated by it's author. We created a fork here: https://github.com/Yakifo/amqtt

I like this change and would like to include it in our fork.

Would you be interested to create your MR there as well?

Thanks :)

[lrasku]

Closing this pull request as this repo is no longer maintained. It has now been merged in Yakifo/amqtt#28.