Support `tls` deferring to vault for list of keys or trusted certificates, support `filesystem` vault

[jfallows]

For the tls client or server.

Possible config options, perhaps there is a better one.

options
  keys: *
  trust: *

Explicitly list aliases in vault implementation like filesystem, default to all in key store.

[jfallows]

No longer required.

The vault should take responsibility for mapping from alias to internal representation as needed.