[8.13](backport #3791) [Azure docs] Add Azure monitoring docs

[mergify]

This PR creates a new Azure monitoring section that includes:

• the existing Azure tutorials, Monitor Microsoft Azure with Elastic Agent, Monitor Microsoft Azure with the Azure Native ISV Service, Monitor Microsoft Azure with Beats, that are currently under Tutorials.
• a new use case on how to collect any metrics using the generic Azure Monitor integration
  Relates to [Azure docs] Add a new section on Azure monitoring #3742

Here is a doc preview of the current status.

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This is an automatic backport of pull request #3791 done by [Mergify](https://mergify.com).

[github-actions]

A documentation preview will be available soon.

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[mergify]

This pull request has not been merged yet. Could you please review and merge it @alaudazzi? 🙏

[alaudazzi]

LGTM