Enc: add unicode case mappings (#5956)

Author: Ehab-24

librz/include/rz_util/rz_unicode.h

@@ -43,6 +43,13 @@ typedef struct rz_unicode_range_entry_t RzUnicodeRangeTable[];
  */
 typedef ut32 RzCodePoint;
 
+typedef struct rz_unicode_case_mapping_t {
+	RzCodePoint key;
+	RzCodePoint val[3];
+} RzUnicodeCaseMapping;
+
+typedef RzUnicodeCaseMapping RzUnicodeCaseMap[];
+
 RZ_API bool rz_unicode_code_point_is_printable(const RzCodePoint c);
 RZ_API bool rz_unicode_code_point_is_defined(const RzCodePoint c);
 RZ_API bool rz_unicode_code_point_is_legal_decode(const RzCodePoint c);
@@ -53,5 +60,9 @@ RZ_API bool rz_unicode_code_point_is_format(const RzCodePoint c);
 RZ_API RzStrEnc rz_unicode_bom_encoding(const ut8 *ptr, size_t ptrlen);
 RZ_API void rz_unicode_code_point_escape(RzCodePoint code_point, RZ_NONNULL RZ_OUT char **dst, RZ_NONNULL const RzStrEscOptions *opt);
 RZ_API void rz_unicode_byte_escape(char ch, RZ_NONNULL RZ_OUT char **dst, RZ_NONNULL const RzStrEscOptions *opt);
+RZ_API RzUnicodeCaseMapping rz_unicode_case_mapping_default(RzCodePoint key);
+RZ_API bool rz_unicode_case_mapping_is_empty(RZ_NULLABLE const RzUnicodeCaseMapping *um);
+RZ_API RzUnicodeCaseMapping rz_unicode_code_point_find_lower(RzCodePoint c);
+RZ_API RzUnicodeCaseMapping rz_unicode_code_point_find_upper(RzCodePoint c);
 
 #endif // RZ_UNICODE_H

librz/include/rz_util/rz_utf8.h

@@ -18,9 +18,11 @@ RZ_API int rz_mutf8_decode(const ut8 *ptr, int ptrlen, RzCodePoint *ch);
 RZ_API int rz_utf8_encode_str(const RzCodePoint *str, ut8 *dst, const int dst_length);
 RZ_API int rz_utf8_size(const ut8 *ptr);
 RZ_API size_t rz_utf8_strlen(const ut8 *str);
+RZ_API size_t rz_utf8_strnlen(RZ_NULLABLE const ut8 *str, size_t maxlen);
 RZ_API const char *rz_utf_block_name(int idx);
 RZ_API int rz_utf_block_idx(RzCodePoint ch);
 RZ_API int *rz_utf_block_list(const ut8 *str, int len, int **freq_list);
+RZ_API size_t rz_utf8_byte_length(RzCodePoint c);
 #if __WINDOWS__
 #define rz_utf16_to_utf8(wc)      rz_utf16_to_utf8_l((wchar_t *)wc, -1)
 #define rz_utf8_to_utf16(cstring) rz_utf8_to_utf16_l((char *)cstring, -1)