Update flatbuffers to v22.9.29 (#26)

* update flatbuffers files

How:
- Copied files in from the latest release (v22.9.29) of flatbuffers

Why:
- The files in place blocked compilation within Alpine Linux

Links:
- https://github.com/felt/tippecanoe/issues/24
- https://github.com/google/flatbuffers/releases/tag/v22.9.29

* update flatgeobuf generate files

How
- Created `feature_generated.h` & `header_generated.h` using the `src/fbs` files from the latest release (3.23.1) of flatgeobuf
    - Downloaded the `flatc` binary from the v22.9.29 release of flatbuffers
    - Copied `flatc` into the flatgeobuf repository
    - Created a new directory named `out` to collect the generated files
    - `./flatc --cpp -o out -I include src/fbs/feature.fbs`
    - `./flatc --cpp -o out -I include src/fbs/header.fbs`
    - Moved the generate files from `out` into this repository's `flatgeobuf` directory

Why
- This is a required step in the process of updating flatbuffers files

Links
- https://github.com/flatgeobuf/flatgeobuf/releases/tag/3.23.1
- https://github.com/google/flatbuffers/releases/tag/v22.9.29
- https://github.com/felt/tippecanoe/issues/24#issuecomment-1286476550

flatbuffers/util.h

@@ -17,19 +17,20 @@
 #ifndef FLATBUFFERS_UTIL_H_
 #define FLATBUFFERS_UTIL_H_
 
+#include <ctype.h>
 #include <errno.h>
 
 #include "flatbuffers/base.h"
 #include "flatbuffers/stl_emulation.h"
 
 #ifndef FLATBUFFERS_PREFER_PRINTF
+#  include <iomanip>
 #  include <sstream>
 #else  // FLATBUFFERS_PREFER_PRINTF
 #  include <float.h>
 #  include <stdio.h>
 #endif  // FLATBUFFERS_PREFER_PRINTF
 
-#include <iomanip>
 #include <string>
 
 namespace flatbuffers {
@@ -94,7 +95,7 @@ template<typename T> size_t IntToDigitCount(T t) {
   // Count a single 0 left of the dot for fractional numbers
   if (-1 < t && t < 1) digit_count++;
   // Count digits until fractional part
-  T eps = std::numeric_limits<float>::epsilon();
+  T eps = std::numeric_limits<T>::epsilon();
   while (t <= (-1 + eps) || (1 - eps) <= t) {
     t /= 10;
     digit_count++;
@@ -254,7 +255,7 @@ inline void strtoval_impl(double *val, const char *str, char **endptr) {
 }
 
 // UBSAN: double to float is safe if numeric_limits<float>::is_iec559 is true.
-__supress_ubsan__("float-cast-overflow")
+__suppress_ubsan__("float-cast-overflow")
 inline void strtoval_impl(float *val, const char *str, char **endptr) {
   *val = __strtof_impl(str, endptr);
 }
@@ -447,6 +448,9 @@ std::string StripPath(const std::string &filepath);
 // Strip the last component of the path + separator.
 std::string StripFileName(const std::string &filepath);
 
+std::string StripPrefix(const std::string &filepath,
+                        const std::string &prefix_to_remove);
+
 // Concatenates a path with a filename, regardless of whether the path
 // ends in a separator or not.
 std::string ConCatPathFileName(const std::string &path,
@@ -681,8 +685,31 @@ bool SetGlobalTestLocale(const char *locale_name,
 bool ReadEnvironmentVariable(const char *var_name,
                              std::string *_value = nullptr);
 
-// MSVC specific: Send all assert reports to STDOUT to prevent CI hangs.
-void SetupDefaultCRTReportMode();
+enum class Case {
+  kUnknown = 0,
+  // TheQuickBrownFox
+  kUpperCamel = 1,
+  // theQuickBrownFox
+  kLowerCamel = 2,
+  // the_quick_brown_fox
+  kSnake = 3,
+  // THE_QUICK_BROWN_FOX
+  kScreamingSnake = 4,
+  // THEQUICKBROWNFOX
+  kAllUpper = 5,
+  // thequickbrownfox
+  kAllLower = 6,
+  // the-quick-brown-fox
+  kDasher = 7,
+  // THEQuiCKBr_ownFox (or whatever you want, we won't change it)
+  kKeep = 8,
+  // the_quick_brown_fox123 (as opposed to the_quick_brown_fox_123)
+  kSnake2 = 9,
+};
+
+// Convert the `input` string of case `input_case` to the specified `output_case`.
+std::string ConvertCase(const std::string &input, Case output_case,
+                    Case input_case = Case::kSnake);
 
 }  // namespace flatbuffers