repect color_config.header color for record key (#16006)

# Description

This PR fixes an oversight where the record key value was not being
colored as the color_config.header color when used with the `table`
command in some circumstances. It respected it with `table -e` but just
not `table`.

### Before

![image](https://github.com/user-attachments/assets/a41e609f-9b3a-415b-af90-037e6ee47318)

### After

![image](https://github.com/user-attachments/assets/c3afb293-ebb3-4cb3-8ee6-4f7e2e96723b)


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crates/nu-table/src/types/general.rs

@@ -40,9 +40,13 @@ fn list_table(input: Vec<Value>, opts: TableOpts<'_>) -> Result<Option<String>,
     Ok(table)
 }
 
+fn get_key_style(topts: &TableOpts<'_>) -> TextStyle {
+    get_header_style(&topts.style_computer).alignment(nu_color_config::Alignment::Left)
+}
+
 fn kv_table(record: Record, opts: TableOpts<'_>) -> StringResult {
     let mut table = NuTable::new(record.len(), 2);
-    table.set_index_style(TextStyle::default_field());
+    table.set_index_style(get_key_style(&opts));
     table.set_indent(opts.config.table.padding);
 
     for (i, (key, value)) in record.into_iter().enumerate() {