Add --color always|never|auto interface (#1049)

Extends #1048 interface providing a more general interface that I think
should be standard.

Allows forcing colors to be on _or_ off. e.g. `NO_COLOR=1 pip install
pip-tools --color always` would be colored.

Hides the `--no-color` option as it only exists for compatibility (and
seems better than throwing an error when people assume it will exist).

Has a nice side-effect of documenting our coloring behaviors e.g.

```
--color <COLOR>
    Control colors in output
    
    [default: auto]

    Possible values:
    - auto:   Enables colored output only when the output is going to a terminal or TTY with support
    - always: Enables colored output regardless of the detected environment
    - never:  Disables colored output
```

crates/puffin/src/main.rs

@@ -57,14 +57,46 @@ struct Cli {
     #[arg(global = true, long, short, conflicts_with = "quiet")]
     verbose: bool,
 
-    /// Disable colors.
+    /// Disable colors; provided for compatibility with `pip`.
-    #[arg(global = true, long)]
+    #[arg(global = true, long, hide = true, conflicts_with = "color")]
     no_color: bool,
 
+    /// Control colors in output.
+    #[arg(
+        global = true,
+        long,
+        value_enum,
+        default_value = "auto",
+        conflicts_with = "no_color"
+    )]
+    color: ColorChoice,
+
     #[command(flatten)]
     cache_args: CacheArgs,
 }
 
+#[derive(Debug, Clone, clap::ValueEnum)]
+pub enum ColorChoice {
+    /// Enables colored output only when the output is going to a terminal or TTY with support.
+    Auto,
+
+    /// Enables colored output regardless of the detected environment.
+    Always,
+
+    /// Disables colored output.
+    Never,
+}
+
+impl ColorChoice {
+    fn to_anstream(&self) -> anstream::ColorChoice {
+        match self {
+            Self::Auto => anstream::ColorChoice::Auto,
+            Self::Always => anstream::ColorChoice::Always,
+            Self::Never => anstream::ColorChoice::Never,
+        }
+    }
+}
+
 #[derive(Subcommand)]
 #[allow(clippy::large_enum_variant)]
 enum Commands {
@@ -558,6 +590,8 @@ async fn inner() -> Result<ExitStatus> {
 
     if cli.no_color {
         anstream::ColorChoice::write_global(anstream::ColorChoice::Never);
+    } else {
+        anstream::ColorChoice::write_global(cli.color.to_anstream());
     }
 
     miette::set_hook(Box::new(|_| {