Box ShellError in Value::Error (#8375)

# Description

Our `ShellError` at the moment has a `std::mem::size_of<ShellError>` of
136 bytes (on AMD64). As a result `Value` directly storing the struct
also required 136 bytes (thanks to alignment requirements).

This change stores the `Value::Error` `ShellError` on the heap.

Pro:
- Value now needs just 80 bytes
- Should be 1 cacheline less (still at least 2 cachelines)

Con:
- More small heap allocations when dealing with `Value::Error`
  - More heap fragmentation
  - Potential for additional required memcopies

# Further code changes

Includes a small refactor of `try` due to a type mismatch in its large
match.

# User-Facing Changes

None for regular users.

Plugin authors may have to update their matches on `Value` if they use
`nu-protocol`

Needs benchmarking to see if there is a benefit in real world workloads.
**Update** small improvements in runtime for workloads with high volume
of values. Significant reduction in maximum resident set size, when many
values are held in memory.

# Tests + Formatting

crates/nu-command/src/conversions/fill.rs

@@ -193,12 +193,12 @@ fn action(input: &Value, args: &Arguments, span: Span) -> Value {
         // Propagate errors by explicitly matching them before the final case.
         Value::Error { .. } => input.clone(),
         other => Value::Error {
-            error: ShellError::OnlySupportsThisInputType {
+            error: Box::new(ShellError::OnlySupportsThisInputType {
                 exp_input_type: "int, filesize, float, string".into(),
                 wrong_type: other.get_type().to_string(),
                 dst_span: span,
                 src_span: other.expect_span(),
-            },
+            }),
         },
     }
 }