kernel32/locale: Add support for LOCALE_RETURN_GENITIVE_NAMES for LOCALE_SMONTHNAME* locale data, update Russian nls resource accordingly.

crypt32: Encode public keys with NULL parameters if they're empty (and make tests more restrictive).

This is necessary because the publicly callable form embeds the asn.1
NULL value when the parameters are empty, whereas the hash value
expects that it's missing.

The function table_find_insert_idx() is replaced by the more generic
function find_insert_index().