Enable Structured Azure Firewall logs for TRE firewall

[ashis-kar91]

Description

There's new analytics view available in Azure Firewall that gives a view of how many times a rule was hit with drilldown. This is good to explore if a rule is needed or not.

To use it, new log categories in the Firewall's diagnostic settings should be turned on.

Acceptance criteria

Structured logs should be enabled in the firewall diagnostic settings, as mentioned in the link and shown in the image below.

https://learn.microsoft.com/en-us/azure/firewall/monitor-firewall#enable-structured-logs