Server-side session termination is not properly handled

[james-whiteside]

Description

If a session is terminated server-side, typically due to timeout, Studio does not currently handle it in a graceful manner. An error message pops up indicating the session has been terminated, but the UI remains partially in the in-session state as it is not designed to account for the possibility of no active session. In order to open a new session, the session or transaction button has to be cycled, which often results in further errors, hangs, or crashes.

Environment

1. TypeDB version: Core 2.24.17
2. OS of TypeDB server: GCP
3. Studio version: 2.24.15
4. OS of Studio: MacOS 14.0