allow str from to convert more things to string (#2977)

* allow str from to convert more things to string

* fixed FileSize so it reports with units configured

* added tests

crates/nu-command/tests/commands/str_/mod.rs

@@ -128,7 +128,7 @@ fn converts_to_int() {
             | rename number
             | where number == 1
             | get number
-            
+
         "#
     ));
 
@@ -343,57 +343,6 @@ fn substrings_the_input_and_treats_end_index_as_length_if_blank_end_index_given(
     })
 }
 
-#[test]
-fn from_decimal_correct_trailing_zeros() {
-    let actual = nu!(
-        cwd: ".", pipeline(
-        r#"
-        = 1.23000 | str from -d 3
-        "#
-    ));
-
-    assert!(actual.out.contains("1.230"));
-}
-
-#[test]
-fn from_int_decimal_correct_trailing_zeros() {
-    let actual = nu!(
-        cwd: ".", pipeline(
-        r#"
-        = 1.00000 | str from -d 3
-        "#
-    ));
-
-    assert!(actual.out.contains("1.000"));
-}
-
-#[test]
-fn from_int_decimal_trim_trailing_zeros() {
-    let actual = nu!(
-        cwd: ".", pipeline(
-        r#"
-        = 1.00000 | str from | format "{$it} flat"
-        "#
-    ));
-
-    assert!(actual.out.contains("1 flat")); // "1" would match "1.0"
-}
-
-#[test]
-fn from_table() {
-    let actual = nu!(
-        cwd: ".", pipeline(
-        r#"
-        echo '[{"name": "foo", "weight": 32.377}, {"name": "bar", "weight": 15.2}]'
-        | from json
-        | str from weight -d 2
-        "#
-    ));
-
-    assert!(actual.out.contains("32.38"));
-    assert!(actual.out.contains("15.20"));
-}
-
 #[test]
 fn str_reverse() {
     let actual = nu!(