should in memory table have TableType::Temporary type?

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**

should in memory table have TableType::Temporary type?

**Describe the solution you'd like**

not sure if ::Base is correct given that mem table goes away after process shutdown

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Add any other context or screenshots about the feature request here.

Start by tracing the in-memory table's use of TableType::Base and compare it with the proposed TableType::Temporary semantics. Determine whether process-shutdown lifetime should change the type, then identify the affected behavior and tests needed to verify the selected table type.

Written by the indexing model from the issue text.