feat(wasi): provide default implementations for WasiFile (#3904)

Additionally, as cleanup, remove duplicate implementations.

crates/wasi-common/cap-std-sync/src/file.rs

@@ -26,9 +26,6 @@ impl WasiFile for File {
     fn as_any(&self) -> &dyn Any {
         self
     }
-    async fn sock_accept(&mut self, _fdflags: FdFlags) -> Result<Box<dyn WasiFile>, Error> {
-        Err(Error::badf())
-    }
     async fn datasync(&self) -> Result<(), Error> {
         self.0.sync_data()?;
         Ok(())
@@ -128,12 +125,6 @@ impl WasiFile for File {
     fn isatty(&self) -> bool {
         self.0.is_terminal()
     }
-    async fn readable(&self) -> Result<(), Error> {
-        Err(Error::badf())
-    }
-    async fn writable(&self) -> Result<(), Error> {
-        Err(Error::badf())
-    }
 }
 
 pub fn filetype_from(ft: &cap_std::fs::FileType) -> FileType {