Fixed missing public access modifiers

[piotrpio]

Added public access modifiers in several places:

• JetStream structs (StreamConfig, StreamInfo etc.)
• JetStream context methods (wait() and request()). I am not sure if request() should be public though, so that needs to be discussed.
• logger - we should think of a better approach to logger configuration instead of global public var, but that can be done as a separate issue
• several Error structs

Signed-off-by: Piotr Piotrowski piotr@synadia.com

[Jarema]

LGTM!

[mtmk]

LGTM