Remove fmt after deprecation (#15040)

# Description
Follow up to https://github.com/nushell/nushell/pull/14875
# User-Facing Changes
`fmt` will be gone for good.

Use it under the new name `format number`

## Note
Can be removed ahead of the `0.103.0` release as it was deprecated with
`0.102.0`

crates/nu-cmd-extra/src/extra/conversions/fmt.rs

@@ -1,74 +0,0 @@
-use nu_engine::command_prelude::*;
-use nu_protocol::{report_parse_warning, ParseWarning};
-
-#[derive(Clone)]
-pub struct Fmt;
-
-impl Command for Fmt {
-    fn name(&self) -> &str {
-        "fmt"
-    }
-
-    fn description(&self) -> &str {
-        "Format a number."
-    }
-
-    fn signature(&self) -> nu_protocol::Signature {
-        Signature::build("fmt")
-            .input_output_types(vec![(Type::Number, Type::record())])
-            .category(Category::Deprecated)
-    }
-
-    fn search_terms(&self) -> Vec<&str> {
-        vec![]
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Get a record containing multiple formats for the number 42",
-            example: "42 | fmt",
-            result: Some(Value::test_record(record! {
-                    "binary" =>   Value::test_string("0b101010"),
-                    "debug" =>    Value::test_string("42"),
-                    "display" =>  Value::test_string("42"),
-                    "lowerexp" => Value::test_string("4.2e1"),
-                    "lowerhex" => Value::test_string("0x2a"),
-                    "octal" =>    Value::test_string("0o52"),
-                    "upperexp" => Value::test_string("4.2E1"),
-                    "upperhex" => Value::test_string("0x2A"),
-            })),
-        }]
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        let head = call.head;
-        report_parse_warning(
-            &StateWorkingSet::new(engine_state),
-            &ParseWarning::DeprecatedWarning {
-                old_command: "fmt".into(),
-                new_suggestion: "use `format number`".into(),
-                span: head,
-                url: "`help format number`".into(),
-            },
-        );
-        crate::extra::strings::format::format_number(engine_state, stack, call, input)
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn test_examples() {
-        use crate::test_examples;
-
-        test_examples(Fmt {})
-    }
-}

crates/nu-cmd-extra/src/extra/conversions/mod.rs

@@ -1,3 +0,0 @@
-mod fmt;
-
-pub(crate) use fmt::Fmt;

crates/nu-cmd-extra/src/extra/mod.rs

@@ -1,5 +1,4 @@
 mod bits;
-mod conversions;
 mod filters;
 mod formats;
 mod math;
@@ -29,8 +28,6 @@ pub fn add_extra_command_context(mut engine_state: EngineState) -> EngineState {
             };
         }
 
-        bind_command!(conversions::Fmt);
-
         bind_command!(
             filters::UpdateCells,
             filters::EachWhile,

crates/nu-cmd-extra/src/extra/strings/format/mod.rs

@@ -5,5 +5,4 @@ mod number;
 pub(crate) use command::FormatPattern;
 // TODO remove `format_bits` visibility after removal of into bits
 pub(crate) use bits::{format_bits, FormatBits};
-// TODO remove `format_number` visibility after removal of into bits
+pub(crate) use number::FormatNumber;
-pub(crate) use number::{format_number, FormatNumber};