Text:CSV_XS has a native builtin way to delete trailing and leading whitespace:

my $csv= text::CSV_XS->new ({ binary => 1, allow_whitespace => 1, auto
+_diag => 1 });
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But that would not help in this case for two reasons

• It does not strip whitespace inside quotation, but only surrounding sep_char:

         allow_whitespace
             When this option is set to true, whitespace (TAB's and SPAC
  +E's)
             surrounding the separation character is removed when parsin
  +g. If
             either TAB or SPACE is one of the three major characters
             "sep_char", "quote_char", or "escape_char" it will not be
             considered whitespace.
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• Thee whitespace stripped is only space or TAB's, and not non-breaking Unicode space stuff

Spreadsheet::Read however offers to strip leading and trailing whitespace from every field. I could extend that on request to allow it to strip Unicode whitespace too.

         strip
           If set, "ReadData ()" will remove trailing- and/or leading-
           whitespace from every field.

             strip  leading  strailing
             -----  -------  ---------
               0      n/a      n/a
               1     strip     n/a
               2      n/a     strip
               3     strip    strip
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