Add Litematica exporter and integrate serde for serialization

- Introduced Litematica exporter with necessary data structures for Minecraft text generation.
- Added serde dependency for serialization support in multiple crates.
- Updated Cargo.toml files to include new dependencies and features.
- Created palette module for block palette management.

crates/exporters/Cargo.toml

@@ -5,6 +5,9 @@ edition = "2024"
 
 [dependencies]
 lib = { path = "../lib" }
+fastnbt = "2.6.1"
+flate2 = "1.1.9"
 anyhow = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
+serde = { workspace = true }