Further cleanup of Span::test_data usage + span fixes (#7595)

# Description

Inspired by #7592

For brevity use `Value::test_{string,int,float,bool}`

Includes fixes to commands that were abusing `Span::test_data` in their
implementation. Now the call span is used where possible or the explicit
`Span::unknonw` is used.

## Command fixes
- Fix abuse of `Span::test_data()` in `query_xml`
- Fix abuse of `Span::test_data()` in `term size`
- Fix abuse of `Span::test_data()` in `seq date`
- Fix two abuses of `Span::test_data` in `nu-cli`
- Change `Span::test_data` to `Span::unknown` in `keybindings listen`
- Add proper call span to `registry query`
- Fix span use in `nu_plugin_query`
- Fix span assignment in `select`
- Use `Span::unknown` instead of `test_data` in more places

## Other
- Use `Value::test_int`/`test_float()` consistently
- More `test_string` and `test_bool`
- Fix unused imports


# User-Facing Changes

Some commands may now provide more helpful spans for downstream use in
errors

crates/nu-command/src/core_commands/hide.rs

@@ -1,7 +1,7 @@
 use nu_protocol::ast::{Call, Expr, Expression};
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
+    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -85,7 +85,7 @@ This command is a parser keyword. For details, check:
             Example {
                 description: "Hide an environment variable",
                 example: r#"let-env HZ_ENV_ABC = 1; hide HZ_ENV_ABC; 'HZ_ENV_ABC' in (env).name"#,
-                result: Some(Value::boolean(false, Span::test_data())),
+                result: Some(Value::test_bool(false)),
             },
         ]
     }

crates/nu-command/src/core_commands/hide_env.rs

@@ -2,8 +2,8 @@ use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
-    did_you_mean, Category, Example, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
+    did_you_mean, Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Type, Value,
 };
 
 #[derive(Clone)]
@@ -70,7 +70,7 @@ impl Command for HideEnv {
         vec![Example {
             description: "Hide an environment variable",
             example: r#"let-env HZ_ENV_ABC = 1; hide-env HZ_ENV_ABC; 'HZ_ENV_ABC' in (env).name"#,
-            result: Some(Value::boolean(false, Span::test_data())),
+            result: Some(Value::test_bool(false)),
         }]
     }
 }

crates/nu-command/src/core_commands/loop_.rs

@@ -2,7 +2,7 @@ use nu_engine::{eval_block, CallExt};
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Block, Command, EngineState, Stack};
 use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
+    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -81,7 +81,7 @@ impl Command for Loop {
         vec![Example {
             description: "Loop while a condition is true",
             example: "mut x = 0; loop { if $x > 10 { break }; $x = $x + 1 }; $x",
-            result: Some(Value::int(11, Span::test_data())),
+            result: Some(Value::test_int(11)),
         }]
     }
 }