Auto merge of #8823 - smoelius:unknown-field, r=xFrednet

Improve "unknown field" error messages

Fixes #8806

Sample output:
```
error: error reading Clippy's configuration file `/home/smoelius/github/smoelius/rust-clippy/clippy.toml`: unknown field `foobar`, expected one of
           allow-expect-in-tests              enable-raw-pointer-heuristic-for-send    standard-macro-braces
           allow-unwrap-in-tests              enforced-import-renames                  third-party
           allowed-scripts                    enum-variant-name-threshold              too-large-for-stack
           array-size-threshold               enum-variant-size-threshold              too-many-arguments-threshold
           avoid-breaking-exported-api        literal-representation-threshold         too-many-lines-threshold
           await-holding-invalid-types        max-fn-params-bools                      trivial-copy-size-limit
           blacklisted-names                  max-include-file-size                    type-complexity-threshold
           cargo-ignore-publish               max-struct-bools                         unreadable-literal-lint-fractions
           cognitive-complexity-threshold     max-suggested-slice-pattern-length       upper-case-acronyms-aggressive
           cyclomatic-complexity-threshold    max-trait-bounds                         vec-box-size-threshold
           disallowed-methods                 msrv                                     verbose-bit-mask-threshold
           disallowed-types                   pass-by-value-size-limit                 warn-on-all-wildcard-imports
           doc-valid-idents                   single-char-binding-names-threshold
       at line 1 column 1
```

You can test this by (say) adding `foobar = 42` to Clippy's root `clippy.toml` file, and running `cargo run --bin cargo-clippy`.

Note that, to get the terminal width, this PR adds `termize` as a dependency to `cargo-clippy`. However, `termize` is also [how `rustc_errors` gets the terminal width](481db40311/compiler/rustc_errors/src/emitter.rs (L1607)). So, hopefully, this is not a dealbreaker.

r? `@xFrednet`

changelog: Enhancements: the "unknown field" error messages for config files now wraps the field names.

clippy_lints/src/lib.rs

@@ -419,7 +419,7 @@ mod zero_sized_map_values;
 // end lints modules, do not remove this comment, it’s used in `update_lints`
 
 pub use crate::utils::conf::Conf;
-use crate::utils::conf::TryConf;
+use crate::utils::conf::{format_error, TryConf};
 
 /// Register all pre expansion lints
 ///
@@ -464,7 +464,7 @@ pub fn read_conf(sess: &Session) -> Conf {
         sess.struct_err(&format!(
             "error reading Clippy's configuration file `{}`: {}",
             file_name.display(),
-            error
+            format_error(error)
         ))
         .emit();
     }