Update azure_monitor output plugin to supported SDK. Current module is EoL in March

Use Case

The Azure authentication module used by the azure_monitor output plugin will be retired in March. Please consider updating the plugin to use azidentity instead.

The notice does indicate the current module will continue to work after March 31st, but that could break at any time in the future without notice - not to mention the increasing risk over time of security incident running an unsupported SDK, and the lack of new feature/compatibility development (e.g. the current plugin isn't compatible with Azure Arc enabled hybrid machines, but would be if it used the newer azidentity SDK)

References:

• azure_monitor: import "github.com/Azure/go-autorest/autorest/azure/auth"
• azure_monitor: auth.NewAuthorizerFromEnvironmentWithResource
• go-autorest/autorest/azure/auth at main · Azure/go-autorest
• Update your Azure SDK libraries by 31 March 2023 | Azure updates | Microsoft Azure:

NOTE: This module will go out of support by March 31, 2023. For authenticating with Azure AD, use module azidentity instead. For help migrating from auth to azidentiy please consult the migration guide. General information about the retirement of this and other legacy modules can be found here.

Expected behavior

N/A

Actual behavior

N/A

Additional info

No response