Moving RedisJSON to a new codebase written in Rust

Dear RedisJSON community members,

We at Redis Labs have been working for a while on some exciting improvements to RedisJSON, which we'd like to share!

First of all, we migrated the codebase from C to Rust. This allows all of us to benefit from one of Rust's central feature: safe code. Memory management is now verified by the compiler, to avoid those ubiquitous security vulnerabilities you've all heard about, such as buffer overflows and remote code execution attacks. In addition, the move to Rust allows us to work on developing new features at a higher velocity than before.

The new codebase already brings some new features:

- Support for the de-facto standard JSONPath. While the original RedisJSON supported a query syntax quite similar to JSONPath, it was still a bit different. This release includes full RedisJSON support, along with backward compatibility with the old query syntax.

Future work in progress:

- We have started working on support for RediSearch integration. While not complete yet, the initial support exists in the codebase and can be tested by those who like bleeding edge technology.