On error, ensure sly-mrepl prompts correct *PACKAGE*

* swank-mrepl.lisp (mrepl-eval): Ensure prompt is sent for
the listeners *PACkAGE* on error.
Trace dialog and multiple inspector fixes

* sly.el (sly-with-popup-buffer): Add `same-window-p'
parameter. By default, inhibit same window if current and target
major modes don't match.
(sly--inspector-buffer): Remove function.
(sly--open-inspector): Simplify and fix FIXME.

* contrib/sly-trace-dialog.el
(sly-trace-dialog-shortcut-mode-map): Trace dialog bindings
override normal bindings.
(sly-trace-dialog-spec): Use `sly-eval-for-inspector'
(sly-trace-dialog-spec): Use a specific inspector name for trace
entries.