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/network/port.rs

@@ -5,7 +5,7 @@ use nu_protocol::IntoPipelineData;
 use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpListener};
 
 use nu_protocol::{
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
+    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -51,7 +51,7 @@ impl Command for SubCommand {
             Example {
                 description: "get a free port between 3121 and 4000",
                 example: "port 3121 4000",
-                result: Some(Value::int(3121, Span::test_data())),
+                result: Some(Value::test_int(3121)),
             },
             Example {
                 description: "get a free port from system",