- Previously, exported objects were not handling their fetched objects correctly
  - Tables were not using copies, only widgets were
  - The parent ticket was not being released in many cases (TreeTable, PartitonedTable, PandasTable)
- Refactored so exported objects always follow the same path
  - Just call connection.getObject, which always creates a new ticket for the object
  - Still need to close the widget so it closes the exported objects
- Test by adding debug logging for SessionState:
```py
import jpy
logger = jpy.get_type('org.slf4j.LoggerFactory').getLogger('io.deephaven.server.session.SessionState')
jpy.cast(logger, jpy.get_type('ch.qos.logback.classic.Logger')).setLevel(jpy.get_type('ch.qos.logback.classic.Level').DEBUG)
```

- Now it doesn't need to do the extra round trip

- Have the exported object "own" the ticket until it is taken from it

- Clean up memory leak in JsPartitionedTable, JsFigure, PandasTable with widgets not being closed after being used
- Add a `takeTicket` method to JsWidgetExportedObject to make it clear when ownership of the ticket has been passed on
- Close exported objects that are still owned when closing a widget
- Tested using the steps and scripts provided in the ticket, as well as testing with creating some tables and opening/closing them in the UI
- Fixes deephaven#4903

…rConnection.java

Co-authored-by: Colin Alworth <colin@vertispan.com>

Co-authored-by: Colin Alworth <colin@vertispan.com>

- Can release the ticket of a widget automatically if the server closes the object - no way to reconnect (currently)
- Remove unnecessary closes

…rConnection.java

Co-authored-by: Colin Alworth <colin@vertispan.com>

…t/JsWidget.java

Co-authored-by: Colin Alworth <colin@vertispan.com>

- Made many methods private instead of public
- Renamed methods to `getExported*` to make it clear they are for server-side exports
- Changed default method of `JsWidgetExportedObject.fetch` so this is not a breaking change

- JsTreeTable was using the ticket from the widget directly, which doesn't work now if the widget releases it's ticket when the stream disconnects (fetch-only widgets)
- Need to export the table as an exportedObject so we don't release it entirely
- Will need Colin to review, this seems a little strange.