Feature request: Allow reference to previous expression evaluations in debug console

It's often generally useful to be able to refer to the results of an earlier expression when exploring the state of a program. This is related to #281, but different. And possibly possible to implement.

result.getBlob("details")
> JDBCBlobClient (id=108)
result.getBlob("details").toString()
> "org.hsqldb.jdbc.JDBCBlobClient@63611043" (id=111)
Utils.fromJson(result.getBlob("details").getBinaryStream())
> BuildRequest (id=119)

This could be changed to

result.getBlob("details")
> JDBCBlobClient ($id_108)
$id_108.toString()
> "org.hsqldb.jdbc.JDBCBlobClient@63611043" ($id_111)
Utils.fromJson($id_108.getBinaryStream())
> BuildRequest ($id_119)

This would allow exploring the results from calls where repeating the call would return different results, and would also allow use of APIs that require objects as parameters, for example,

new byte[10000]
> byte[10000] ($id_120)
result.getBlob("details").getBinaryStream().read($id_120, 0, 10000)
> 200
new String($id_120)
> "The string result is displayed here..."

從除錯主控台入口點開始，檢查運算式的評估與顯示方式。定義先前的結果如何取得類似 $id_108 的參照，以及這些參照如何傳遞至後續運算式；完成標準是結果可以重複使用而不必重複呼叫，包括作為物件或陣列引數使用。