Progress bar Implementation (#7661)

# Description

_(Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.)_

I implemented the status bar we talk about yesterday. The idea was
inspired by the progress bar of `wget`.
I decided to go for the second suggestion by `@Reilly`
> 2. add an Option<usize> or whatever to RawStream (and ListStream?) for
situations where you do know the length ahead of time

For now only works with the command `save` but after the approve of this
PR we can see how we can implement it on commands like `cp` and `mv`

When using `fetch` nushell will check if there is any `content-length`
attribute in the request header. If so, then `fetch` will send it
through the new `Option` variable in the `RawStream` to the `save`.
If we know the total size we show the progress bar 

![nu_pb01](https://user-images.githubusercontent.com/38369407/210298647-07ee55ea-e751-41b1-a84d-f72ec1f6e9e5.jpg)
but if we don't then we just show the stats like: data already saved,
bytes per second, and time lapse.

![nu_pb02](https://user-images.githubusercontent.com/38369407/210298698-1ef65f51-40cc-4481-83de-309cbd1049cb.jpg)

![nu_pb03](https://user-images.githubusercontent.com/38369407/210298701-eef2ef13-9206-4a98-8202-e4fe5531d79d.jpg)

Please let me know If I need to make any changes and I will be happy to
do it.

# User-Facing Changes

A new flag (`--progress` `-p`) was added to the `save` command 
Examples:
```nu
fetch https://github.com/torvalds/linux/archive/refs/heads/master.zip | save --progress -f main.zip
fetch https://releases.ubuntu.com/22.04.1/ubuntu-22.04.1-desktop-amd64.iso | save --progress -f main.zip
open main.zip --raw | save --progress main.copy
```

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
-
I am getting some errors and its weird because the errors are showing up
in files i haven't touch. Is this normal?

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

Co-authored-by: Reilly Wood <reilly.wood@icloud.com>

crates/nu-command/src/network/fetch.rs

@@ -361,6 +361,26 @@ fn response_to_buffer(
     engine_state: &EngineState,
     span: Span,
 ) -> nu_protocol::PipelineData {
+    // Try to get the size of the file to be downloaded.
+    // This is helpful to show the progress of the stream.
+    let buffer_size = match &response.headers().get("content-length") {
+        Some(content_length) => {
+            let content_length = &(*content_length).clone(); // binding
+
+            let content_length = content_length
+                .to_str()
+                .unwrap_or("")
+                .parse::<u64>()
+                .unwrap_or(0);
+
+            if content_length == 0 {
+                None
+            } else {
+                Some(content_length)
+            }
+        }
+        _ => None,
+    };
     let buffered_input = BufReader::new(response);
 
     PipelineData::ExternalStream {
@@ -370,6 +390,7 @@ fn response_to_buffer(
             }),
             engine_state.ctrlc.clone(),
             span,
+            buffer_size,
         )),
         stderr: None,
         exit_code: None,

crates/nu-command/src/network/post.rs

@@ -415,6 +415,7 @@ fn response_to_buffer(
             }),
             engine_state.ctrlc.clone(),
             span,
+            None,
         )),
         stderr: None,
         exit_code: None,