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..."

デバッグコンソールのエントリポイントから始め、式がどのように評価され、表示されるかを調べます。以前の結果が $id_108 のような参照を受け取り、それらの参照を後続の式に渡せる方法を定義します。呼び出しを繰り返さずに結果を再利用でき、オブジェクトや配列の引数としても使用できれば完了です。