Following from #1644, these are the methods in the public interface of FluentConnection:

svar_data

• should be added only to solver session classes

id

• identifies a session, should be part of the base session

get_current_fluent_mode

• not needed, can be a direct API call from the launcher code

start_transcript
stop_transcript

• now completely redundant due to transcript.start(), transcript.stop() which are the tested methods
• also, we can update the docstring in launcher.py accordingly

start_journal
stop_journal

• these are general-purpose session methods; add to session base class

check_health

• checks the health of the connection. Retain here

get_fluent_version

• add to base session

exit

• belongs here