Make the name field of the Key Info Manager optional

[hug-dev]

The name field of the key_manager section of the configuration is currently required:

[[key_manager]]
# (Required) Name of the key info manager. Used to tie providers to the manager supporting them.
name = "on-disk-manager"

That name is used for each provider to select it. In some conditions, if there is only one for example, that name could be made optional and all providers would use it directly. The name field could only be required when there is more than one KIM of the same type.

[ionut-arm]

The name field could only be required when there is more than one KIM of the same type.

You need a name if you have multiple KIMs of any type, because otherwise there's no way to tell which one to use for a specific provider (there's no field in provider configs to indicate the type you want to use, just the name).