Display empty records and lists (#7925)

# Description

Fix some issues related to #7444 
1. Empty lists and records are now displayed as a small notice in a box:

![image](https://user-images.githubusercontent.com/17511668/215832023-3f8d743a-2899-416f-9109-7876ad2bbedf.png)

![image](https://user-images.githubusercontent.com/17511668/215832273-c737b8a4-af33-4c16-8dd3-bd4f0fd19b5a.png)
2. Empty records are now correctly displayed if inside of another record
list or table:

![image](https://user-images.githubusercontent.com/17511668/215832597-00f0cebc-a3b6-4ce8-8373-a9340d4c7020.png)

![image](https://user-images.githubusercontent.com/17511668/215832540-ab0e2a14-b8f6-4f47-976c-42003b622ef6.png)
3. Fixed inconsistent coloring of empty list placeholder inside of
lists/tables:

![image](https://user-images.githubusercontent.com/17511668/215832924-813ffe17-e04e-4301-97c3-1bdbccf1825c.png)

![image](https://user-images.githubusercontent.com/17511668/215832963-4765c4cf-3036-4bcc-81e1-ced941fa47cb.png)


# User-Facing Changes

`table` command now displays empty records and lists like a table with
text and correctly displays empty records inside tables and lists.

New behavior of displaying empty lists and records can be disabled using
`table.show_empty` config option.

# 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

# 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.

crates/nu-protocol/src/config.rs

@@ -65,6 +65,7 @@ pub struct Config {
     pub external_completer: Option<usize>,
     pub filesize_metric: bool,
     pub table_mode: String,
+    pub table_show_empty: bool,
     pub use_ls_colors: bool,
     pub color_config: HashMap<String, Value>,
     pub use_grid_icons: bool,
@@ -106,6 +107,7 @@ impl Default for Config {
         Config {
             filesize_metric: false,
             table_mode: "rounded".into(),
+            table_show_empty: true,
             external_completer: None,
             use_ls_colors: true,
             color_config: HashMap::new(),
@@ -885,6 +887,9 @@ impl Value {
                                             }
                                         }
                                     }
+                                    "show_empty" => {
+                                        try_bool!(cols, vals, index, span, table_show_empty)
+                                    }
                                     x => {
                                         invalid_key!(
                                             cols,

crates/nu-protocol/src/ty.rs

@@ -96,6 +96,35 @@ impl Type {
             Type::Signature => SyntaxShape::Signature,
         }
     }
+
+    /// Get a string representation, without inner type specification of lists,
+    /// tables and records (get `list` instead of `list<any>`
+    pub fn get_non_specified_string(&self) -> String {
+        match self {
+            Type::Block => String::from("block"),
+            Type::Closure => String::from("closure"),
+            Type::Bool => String::from("bool"),
+            Type::CellPath => String::from("cell path"),
+            Type::Date => String::from("date"),
+            Type::Duration => String::from("duration"),
+            Type::Filesize => String::from("filesize"),
+            Type::Float => String::from("float"),
+            Type::Int => String::from("int"),
+            Type::Range => String::from("range"),
+            Type::Record(_) => String::from("record"),
+            Type::Table(_) => String::from("table"),
+            Type::List(_) => String::from("list"),
+            Type::Nothing => String::from("nothing"),
+            Type::Number => String::from("number"),
+            Type::String => String::from("string"),
+            Type::ListStream => String::from("list stream"),
+            Type::Any => String::from("any"),
+            Type::Error => String::from("error"),
+            Type::Binary => String::from("binary"),
+            Type::Custom(_) => String::from("custom"),
+            Type::Signature => String::from("signature"),
+        }
+    }
 }
 
 impl Display for Type {