bug#67028: 29.1; WDired should restore the previous `mode-name' when returning to Dired mode

[Drew Adams]

Dunno how simple and sure this would be to do, but I think that when you
quit WDired the mode-line should show the same `mode-name' it showed
before you entered WDired.  E.g., if the `mode-name' was "Dired by name"
then it should be restored to that.

Instead, when you quit WDired the `mode-name' is always set to just
"Dired".  You lose the info that the sorting is by name or by date.

Seems like `wdired-change-to-dired-mode' could just save the `mode-name'
before it changes mode.  And then `wdired-change-to-dired-mode' to
restore that saved `mode-name' value.

In GNU Emacs 29.1 (build 2, x86_64-w64-mingw32) of 2023-08-02 built on
 AVALON
Windowing system distributor 'Microsoft Corp.', version 10.0.19045
System Description: Microsoft Windows 10 Pro (v10.0.2009.19045.3570)

Configured using:
 'configure --with-modules --without-dbus --with-native-compilation=aot
 --without-compress-install --with-tree-sitter CFLAGS=-O2'

Configured features:
ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES NATIVE_COMP
NOTIFY W32NOTIFY PDUMPER PNG RSVG SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XPM ZLIB

(NATIVE_COMP present but libgccjit not available)