ICU-22549 Add fuzzer for NumberFormatter #1247

Job	Run time
clang-valgrind-test	10m 1s
clang-valgrind-intltest (utility)	6m 33s
clang-valgrind-intltest (normalize)	6m 7s
clang-valgrind-intltest (collator)	5m 8s
clang-valgrind-intltest (regex)	5m 4s
clang-valgrind-intltest (format)	16m 41s
clang-valgrind-intltest (translit)	5m 44s
clang-valgrind-intltest (rbbi)	7m 25s
clang-valgrind-intltest (rbnf)	5m 45s
clang-valgrind-intltest (rbnfrt)	6m 22s
clang-valgrind-intltest (icuserv)	5m 40s
clang-valgrind-intltest (idna)	5m 7s
clang-valgrind-intltest (convert)	7m 8s
clang-valgrind-intltest (rbnfp)	5m 30s
clang-valgrind-intltest (csdet)	5m 0s
clang-valgrind-intltest (spoof)	5m 26s
clang-valgrind-intltest (bidi)	5m 29s
	1h 54m 10s

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