Fix zlib version parse

Currently cmake scripttry to use regex to parse VER_MAJOR, VER_MINOR,
VER_REVISION from ZLIB_VERSION. However, ZLIB_VERSION is "1.3" which
means that there is no VER_REVISION.
You can reproduce using "-DBUILD_ZLIB=ON"
```
--     ZLib:                        zlib (ver 1.3.#define ZLIB_VERSION "1.3")
```

This patch add a new macro ocv_parse_header_version to extract version
information.

cmake/OpenCVFindLibsGrfmt.cmake

@@ -34,7 +34,7 @@ if(NOT ZLIB_FOUND)
   set(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})
   set(ZLIB_LIBRARIES ${ZLIB_LIBRARY})
 
-  ocv_parse_header2(ZLIB "${${ZLIB_LIBRARY}_SOURCE_DIR}/zlib.h" ZLIB_VERSION)
+  ocv_parse_header_version(ZLIB "${${ZLIB_LIBRARY}_SOURCE_DIR}/zlib.h")
 endif()
 
 # --- libavif (optional) ---

cmake/OpenCVUtils.cmake

@@ -1430,6 +1430,18 @@ macro(ocv_parse_header2 LIBNAME HDR_PATH VARNAME)
   endif()
 endmacro()
 
+# set ${LIBNAME}_VERSION_STRING to ${LIBNAME}_VERSION without quotes
+macro(ocv_parse_header_version LIBNAME HDR_PATH)
+  ocv_clear_vars(${LIBNAME}_VERSION_STRING)
+  set(${LIBNAME}_H "")
+  if(EXISTS "${HDR_PATH}")
+    file(STRINGS "${HDR_PATH}" ${LIBNAME}_H REGEX "^#define[ \t]+${LIBNAME}_VERSION[ \t]+\"[^\"]*\".*$" LIMIT_COUNT 1)
+  endif()
+  if(${LIBNAME}_H)
+    string(REGEX REPLACE "^.*[ \t]${LIBNAME}_VERSION[ \t]+\"([0-9\.]+)\"$" "\\1" ${LIBNAME}_VERSION_STRING "${${LIBNAME}_H}")
+  endif()
+endmacro()
+
 ################################################################################################
 # short command to setup source group
 function(ocv_source_group group)