[AspireDeployment] azd should search for 'azure.yml' file in parent directories

[anvillan]

azd should look up the azure.yml file in the parent directory of the current-working-directory if not found.

When the repository structure separates the source code from the root of the repo, it could happen that the azure.yml files is not sibling to the AppHost project. I.e.:

\repo -\azure.yaml -\src --\app.apphost --\app.foo --\app.bar

So, the azure.yml is in my repo root (\repo), not the solution root (\repo\src).

When VS IDE starts the azd vs-server pass in the --cwd with the Solution root directory.

This pattern of having code in \src is not uncommon.