tools: fix iculslocs to support ICU 65.1

The ICU alias table format changed in
https://unicode-org.atlassian.net/browse/ICU-20627

Because of this, iculslocs.cc needs to handle URES_TABLE format
contents in the res_index.txt file.

PR-URL: https://github.com/nodejs/node/pull/29523


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>