ICU-23358 Make RBNF lenient parsing of ignorables more consistent between locales #5153

Job	Run time
clang-valgrind-test	10m 46s
clang-valgrind-intltest (rbbi)	9m 50s
clang-valgrind-intltest (utility)	7m 26s
clang-valgrind-intltest (format)	16m 30s
clang-valgrind-intltest (normalize)	6m 43s
clang-valgrind-intltest (collator)	5m 33s
clang-valgrind-intltest (translit)	6m 51s
clang-valgrind-intltest (regex)	10m 11s
clang-valgrind-intltest (spoof)	6m 1s
clang-valgrind-intltest (icuserv)	5m 45s
clang-valgrind-intltest (rbnf)	6m 0s
clang-valgrind-intltest (rbnfp)	5m 19s
clang-valgrind-intltest (csdet)	5m 55s
clang-valgrind-intltest (idna)	4m 57s
clang-valgrind-intltest (bidi)	5m 52s
clang-valgrind-intltest (rbnfrt)	6m 37s
clang-valgrind-intltest (convert)	6m 56s
	2h 7m 12s

Provide feedback