extended StringifyError

removed usage of deprecated std.array_list.Managed in favor of std.Io…

….Writer.Allocating (for u8 slices) and std.ArrayListUnmanaged.

updated package to Zig compiler version 0.15.1

bumped up version to 0.18.0

bumped up version to 0.17.3

fixed error where ArrayBackedSlice writers couldn't be used with seri…

…alize()

Merge pull request #27 from kj4tmp/stringify-to-fbs

support stringify to a fixed buffer stream

fixed change regarding pop() introduced with 0.14.0

bumped supported version to Zig 0.14.0 (to be released soon)

writeFloat and GetFloatN added