Remove fs_extra (#655)

* WIP Remove fs_extra

* Finish removing fs_extra

examples/copy.rs

@@ -0,0 +1,30 @@
+use cosmic_files::operation::{recursive::Context, ReplaceResult};
+use std::{error::Error, io};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut context = Context::new()
+        .on_progress(|op, progress| {
+            println!("{:?}: {:?}", op.to, progress);
+        })
+        .on_replace(|op| {
+            println!("replace {:?}? (y/N)", op.to);
+            let mut line = String::new();
+            match io::stdin().read_line(&mut line) {
+                Ok(_) => {
+                    if line == "y" {
+                        ReplaceResult::Replace(false)
+                    } else {
+                        ReplaceResult::Skip(false)
+                    }
+                }
+                Err(err) => {
+                    eprintln!("failed to read stdin: {}", err);
+                    ReplaceResult::Cancel
+                }
+            }
+        });
+
+    context.recursive_copy("test/a", "test/b")?;
+    context.recursive_move("test/b", "test/c")?;
+    Ok(())
+}