Support parsing AAD Audience from connection string

[harsimar]

Description

This PR adds support for parsing the AAD Audience from the connection string. If there isn't an audience provided, it will use the default audience and scope (https://monitor.azure.com//.default). This is so we can support AAD auth in sovereign clouds. The AzureMonitorExporterBuilder will call ConnectionString.getAadAudienceWithScope() so that the correct scope is used in http pipeline policies.

There will a PR added in ApplicationInsights-Java repo so that the java agent can also utilize this functionality.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

com.azure:azure-monitor-opentelemetry-autoconfigure