feat: separate zstd and faketcp into features (#1861)

* feat: separate faketcp into a feature
* fix: no need to initialize out_len
* feat: separate zstd into a feature
* clippy: remove unnecessary cast, because for unix size_t always equals usize

easytier/src/proto/common.rs

@@ -330,6 +330,7 @@ impl TryFrom<CompressionAlgoPb> for CompressorAlgo {
 
     fn try_from(value: CompressionAlgoPb) -> Result<Self, Self::Error> {
         match value {
+            #[cfg(feature = "zstd")]
             CompressionAlgoPb::Zstd => Ok(CompressorAlgo::ZstdDefault),
             CompressionAlgoPb::None => Ok(CompressorAlgo::None),
             _ => Err(anyhow::anyhow!("Invalid CompressionAlgoPb")),
@@ -342,6 +343,7 @@ impl TryFrom<CompressorAlgo> for CompressionAlgoPb {
 
     fn try_from(value: CompressorAlgo) -> Result<Self, Self::Error> {
         match value {
+            #[cfg(feature = "zstd")]
             CompressorAlgo::ZstdDefault => Ok(CompressionAlgoPb::Zstd),
             CompressorAlgo::None => Ok(CompressionAlgoPb::None),
         }