Fork that updates underlying simdjson library, makes library faster and add encoding support

[JakubOnderka]

Hello,

I crated a fork of your great library, that is currently still in development and is available at https://github.com/JakubOnderka/simdjson_php

The mains changes are:

• simdjson library is updated to 3.11.3
• contains a lot of new optimizations
• automatically release memory if decoding string longer than 100 MB
• manually release memory by simdjson_cleanup() method
• deduplicates keys in decoded arrays to make decoding faster and require less memory
• add support for SIMD accelerated JSON encoding

I would be happy if you can provide me a feedback to my changes or even if you can help me to prepare Windows build, so this new version can be published to pecl.