ID-1095 null default route

[dvoet]

Ticket: https://broadworkbench.atlassian.net/browse/ID-1095

In my latest iteration of sam metrics on dev I found that when there is an error before we are able to figure out the route (e.g. unregistered user or user has not accepted TOS), the http path is used in the http route metrics tag leading to cardinality issues in dev. This might not be an acute problem in prod but it is a vulnerability. This PR makes the default null which also protects against cardinality problem if route does not update telemetry correctly.

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PR checklist

• I've followed the instructions if I've made any changes to the API, especially if they're breaking changes
• I've filled out the Security Risk Assessment (requires Broad Internal network access) and attached the result to the JIRA ticket

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud