[FEATURE] Port 708 decoder encoding module to RUST

[IshanGrover2004]

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I have migrated the logic and functions from the lib_ccx/ccx_decoder_708_encoding.c file to Rust, located in decoder/encoding.rs. This conversion maintains the same functionality that was originally written in C, now implemented in Rust.

To know more See ccx_decoder_708_encoding.c and compare with File Changed in PR, they are both same

Background & Testing

• Current codebase scenerio: Only C code of ccx_decoder_708_encoding.c file is available. So while making & running Rust test cases which requires these functions do not have body because cargo test is just seeing the rust code only.
• After PR changes: Exact same logic of rust code will be there. And I did also added the conditional compilation so that if user build with -without-rust then only C code will work or else Rust code will build. And Yes I have manually tested that when compiling with rust src files, rust code is being used and giving the same result.