Similar to #93076, there are yet more pieces of information about SQL transactions that would be nice to have in txn insights:

• isolation level (from connExecutor.state.isolationLevel)
• Quality of Service level (for admission control) (might have to be plumbed through from txn.AdmissionHeader().Priority?)
• as of time, if using AS OF SYSTEM TIME (from connExecutor.state.getReadTimestamp() or at least connExecutor.state.isHistorical)
• whether the transaction is read-only (from connExecutor.state.readOnly)

Jira issue: CRDB-29986