Support for multiple server names

[mpflanzer]

I think it would be a nice addition to be able to configure tuwunel to manage multiple server names. For example my use case would be to have @***:my-company.example for internal employees and @***:external.my-company.example for external contractors. The latter would allow to avoid confusion whether a person is internal or external.

I could spin up two servers for this but feels like a waste of resources to federate between to local instances.

For reference, the same is discussed here for synapse: matrix-org/synapse#8885