Better errors when bash-like operators are used

[sophiajt]

Description

Adds improved errors for when a user uses a bashism that nu doesn't support.

fixes #7237

Examples:

Error: nu::parser::shell_andand (link)

  × The '&&' operator is not supported in Nushell
   ╭─[entry #1:1:1]
 1 │ ls && ls
   ·    ─┬
   ·     ╰── instead of '&&', use ';' or 'and'
   ╰────
  help: use ';' instead of the shell '&&', or 'and' instead of the boolean '&&'

Error: nu::parser::shell_oror (link)

  × The '||' operator is not supported in Nushell
   ╭─[entry #8:1:1]
 1 │ ls || ls
   ·    ─┬
   ·     ╰── instead of '||', use 'try' or 'or'
   ╰────
  help: use 'try' instead of the shell '||', or 'or' instead of the boolean '||'

Error: nu::parser::shell_err (link)

  × The '2>' shell operation is 'err>' in Nushell.
   ╭─[entry #9:1:1]
 1 │ foo 2> bar.txt
   ·     ─┬
   ·      ╰── use 'err>' instead of '2>' in Nushell
   ╰────

Error: nu::parser::shell_outerr (link)

  × The '2>&1' shell operation is 'out+err>' in Nushell.
   ╭─[entry #10:1:1]
 1 │ foo 2>&1 bar.txt
   ·     ──┬─
   ·       ╰── use 'out+err>' instead of '2>&1' in Nushell
   ╰────
  help: Nushell redirection will write all of stdout before stderr.

User-Facing Changes

BREAKING CHANGES

This removes the && and || operators. We previously supported by &&/and and ||/or. With this change, only and and or are valid boolean operators.

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 after the PR is merged, if necessary. This will help us keep the docs up to date.

[sholderbach]

Maybe subject to change given #7240 ?

[WindSoilder]

Oh, #7240 will make things different

[sholderbach]

Some of it is messing with quote-less nuon but should probably quoted anyways.