Mini Agent: Extract azure env vars + add tags

[thedavl]

What does this PR do?

Adds logic into the mini agent to process azure env vars, and add the following tags:

• azurefunction.resource.id
• azurefunction.resource.group
• azurefunction.subscription.id
• azurefunction.site.name
• azurefunction.environment.os

The azurefunction.resource.id is constructed in the following format: /subscriptions/<subscription-id>/resourcegroups/<resource-group>/providers/microsoft.web/sites/<site-name>

Motivation

Azure trace tracking

Additional Notes

Anything else we should know when reviewing?

How to test the change?

Describe here in detail how the change can be validated.

For Reviewers

• [ ] If this PR touches code that signs or publishes builds or packages, or handles credentials of any kind, I've requested a review from @DataDog/security-design-and-guidance.
• [ ] This PR doesn't touch any of that.

[gleocadie]

Just a question: could it be reused ? https://github.com/DataDog/libdatadog/blob/8cbc9dbf7b6f32dc5f6a43c62e89421f4c8217d2/ddcommon/src/azure_app_services.rs#L7

[duncanpharvey]

Handled in https://github.com/DataDog/libdatadog/pull/463