stacktrace: fix missing caller frames and remove carets from vd_cli() traces

[midichef]

4df7308 fixes a bug in #2586. The caller of stacktrace() was being removed in too many cases, like in getCell(). Now the only caller of stacktrace that is removed is exceptionCaught().

Test case: vd = 1+[] z^E and note how there is no line that ends with in getCell until after applying 4df7308.

aa4285b cleans up the carets in tracebacks from vd_cli (seen in Python 3.11 and up). Like in the traceback when an HTTP connection closes:

  File "/usr/lib/python3.12/http/client.py", line 331, in begin
    version, status, reason = self._read_status()
                              ^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/http/client.py", line 300, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
http.client.RemoteDisconnected: Remote end closed connection without response

You can test this with netcat: nc -l -p 2000 -w 1& vd http://localhost:2000/

I tested aa4285b in the most recent Python major versions from 3.8-3.12.

Note that the new exception formatting will not happen for events like KeyboardInterrupt. So the carets will be seen if you do vd /dev/zero then hit ^C.