Implement token request with Azure CLI.
Inspired from the Azure C++ SDK's `AzureCliCredential`, this credential
type attempts to run the Azure CLI in a shell and parse the token from
its output. This is meant for development purposes, where a user has
already installed the Azure CLI and logged in with their user account.
Pass the following environment to the process:
* PATH
* HOME
* AZURE_CONFIG_DIR
Add a token factory to construct a token from the process output. Unlike
in Azure Entra and IMDS, the CLI's JSON output does not contain
'expires_in', and the token key is in camel case.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
The goal is to mimic the Azure C++ SDK, which offers a variety of
credentials, depending on their type and source.
Declare the following credentials:
* Service Principal credentials
* Managed Identity credentials
* Azure CLI credentials
* Default credentials
Also, define a common exception for SP and MI credentials which are
network-based.
This patch only defines the API.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>