Move crates under a sub folder to clean up the code

crates/milli/src/heed_codec/mod.rs

@@ -0,0 +1,39 @@
+mod beu16_str_codec;
+mod beu32_str_codec;
+mod byte_slice_ref;
+pub mod facet;
+mod field_id_word_count_codec;
+mod fst_set_codec;
+mod obkv_codec;
+mod roaring_bitmap;
+mod roaring_bitmap_length;
+mod str_beu32_codec;
+mod str_ref;
+mod str_str_u8_codec;
+
+pub use byte_slice_ref::BytesRefCodec;
+use heed::BoxedError;
+pub use str_ref::StrRefCodec;
+use thiserror::Error;
+
+pub use self::beu16_str_codec::BEU16StrCodec;
+pub use self::beu32_str_codec::BEU32StrCodec;
+pub use self::field_id_word_count_codec::FieldIdWordCountCodec;
+pub use self::fst_set_codec::FstSetCodec;
+pub use self::obkv_codec::ObkvCodec;
+pub use self::roaring_bitmap::{BoRoaringBitmapCodec, CboRoaringBitmapCodec, RoaringBitmapCodec};
+pub use self::roaring_bitmap_length::{
+    BoRoaringBitmapLenCodec, CboRoaringBitmapLenCodec, RoaringBitmapLenCodec,
+};
+pub use self::str_beu32_codec::{StrBEU16Codec, StrBEU32Codec};
+pub use self::str_str_u8_codec::{U8StrStrCodec, UncheckedU8StrStrCodec};
+
+pub trait BytesDecodeOwned {
+    type DItem;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Result<Self::DItem, BoxedError>;
+}
+
+#[derive(Error, Debug)]
+#[error("the slice is too short")]
+pub struct SliceTooShortError;