To start with your second question: you can (must) have a centralized location for your code. Usually, this is the Mendix Team Server. You can add a custom SVN repository yourself, if you do not want to use the Mendix Team Server to host your code. In both instances, you can manage multitenant developers.
Looking at Azure DevOps functionality, you may be able to use some of it: Mendix uses SVN as versioning, so you can't really use Github to store your code (merging models from multiple developers will not work). This may present problems when you want to use Azure DevOps’ CI/CD pipelines. A workaround for this is building packages (e.g. using the Mendix Team Server build API) and storing the package in GitHub, where a CI/CD pipeline picks it up. Features such a Azure Boards and Azure Test Plans should be usable for Mendix.