bug#57977: 29.0.50; [PATCH] Make Gnus respect mode-line-buffer-identification-keymap

[Visuwesh]

The buffer name in the mode-line has a keymap set which lets you use
button-1 and button-3 to change the buffer in that window.  However,
gnus-mode-line-buffer-identification does not put the keymap.  This
breaks the flow when you're quickly going through the buffers using the
mouse buttons.  I will attach a patch once I get the bug number.

In GNU Emacs 29.0.50 (build 18, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.16.0, Xaw scroll bars) of 2022-09-20 built on astatine
Repository revision: cd2168cd131852279a7d9257c7dff45224c9d6a9
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101004
System Description: Debian GNU/Linux bookworm/sid

Configured using:
 'configure --with-sound=alsa --with-x-toolkit=lucid --with-json
 --without-xaw3d --without-gconf --without-libsystemd'
Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LIBOTF LIBSELINUX LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XIM
XINPUT2 XPM LUCID ZLIB
Important settings:
  value of $LC_MONETARY: ta_IN.UTF-8
  value of $LC_NUMERIC: ta_IN.UTF-8
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Browse Server

Minor modes in effect:
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  shell-dirtrack-mode: t
  eros-mode: t
  pdf-occur-global-minor-mode: t
  minibuffer-depth-indicate-mode: t
  repeat-mode: t
  display-time-mode: t
  display-battery-mode: t
  winner-mode: t
  acme-tag-minor-mode: t
  delete-selection-mode: t
  xterm-mouse-mode: t
  straight-use-package-mode: t
  straight-package-neutering-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  use-hard-newlines: t
  tab-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  undelete-frame-mode: t
  buffer-read-only: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t