Restrict closure expression to be something like {|| ...} (#8290)

# Description

As title, closes: #7921 closes: #8273

# User-Facing Changes

when define a closure without pipe, nushell will raise error for now:
```
❯ let x = {ss ss}
Error: nu::parser::closure_missing_pipe

  × Missing || inside closure
   ╭─[entry #2:1:1]
 1 │ let x = {ss ss}
   ·         ───┬───
   ·            ╰── Parsing as a closure, but || is missing
   ╰────
  help: Try add || to the beginning of closure
```

`any`, `each`, `all`, `where` command accepts closure, it forces user
input closure like `{||`, or parse error will returned.
```
❯ {major:2, minor:1, patch:4} | values | each { into string }
Error: nu::parser::closure_missing_pipe

  × Missing || inside closure
   ╭─[entry #4:1:1]
 1 │ {major:2, minor:1, patch:4} | values | each { into string }
   ·                                             ───────┬───────
   ·                                                    ╰── Parsing as a closure, but || is missing
   ╰────
  help: Try add || to the beginning of closure
```

`with-env`, `do`, `def`, `try` are special, they still remain the same,
although it says that it accepts a closure, but they don't need to be
written like `{||`, it's more likely a block but can capture variable
outside of scope:
```
❯ def test [input] { echo [0 1 2] | do { do { echo $input } } }; test aaa
aaa
```

Just realize that It's a big breaking change, we need to update config
and scripts...

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-parser/tests/test_parser.rs

@@ -1563,7 +1563,13 @@ mod input_types {
                 )
                 .optional(
                     "else_expression",
-                    SyntaxShape::Keyword(b"else".to_vec(), Box::new(SyntaxShape::Expression)),
+                    SyntaxShape::Keyword(
+                        b"else".to_vec(),
+                        Box::new(SyntaxShape::OneOf(vec![
+                            SyntaxShape::Block,
+                            SyntaxShape::Expression,
+                        ])),
+                    ),
                     "expression or block to run if check fails",
                 )
                 .category(Category::Core)