Refactor quiet! to be less destructive

It's possible for the debugger to be invoked from inside code wrapped in
a (quiet! ...) call. The debugger pauses Emacs in a broken state where
the functions locally rebound by quiet! (e.g. message, load-file,
write-region, etc) are never returned to their original definitions.

This attempts to reduce that probabilityby changing how quiet! silences
code. Rather than silencing them completely, they will be logged
to *Messages* but not displayed in the echo area.

Also, quiet! is now used less, where it isn't strictly needed (or where
inhibit-message is sufficient).

modules/lang/web/test/test-web.el

@@ -40,7 +40,7 @@
 
     (describe "toggle-inline-or-block"
       (after-each
-        (+css/toggle-inline-or-block)
+        (quiet! (+css/toggle-inline-or-block))
         (expect (string-trim (buffer-string)) :to-equal
                 (string-join
                  '("body {"