Add support for web_connectivity 0.5

[hellais]

There are a few changes needed to the observation generation and analysis in order to fully support web_connectivity 0.5.

Things to consider include:

• Support the new transaction based network_events parsing (see: Fix bug in reading TLS network_events #34)
• Consider as part of analysis and potentially observation generation the fact that DNS lookups are not always done via getaddrinfo
• Other logic which is different in wc 0.5 that might impact obs and analysis generation

[hellais]

Inside of #81 support was added for properly parsing and marking the transaction_id inside of observation generation.

[hellais]

I have moved analysis related consideration for web_connectivity 0.5 into here: #95