Rule::noqa_code previously return a single &'static str,
which was possible because we had one enum listing all
rule code prefixes. This commit series will however split up
the RuleCodePrefix enum into several enums ... so we'll end up
with two &'static str ... this commit wraps the return type
of Rule::noqa_code into a newtype so that we can easily change
it to return two &'static str in the 6th commit of this series.
Post this commit series several codes can be mapped to a single rule,
this commit therefore renames Rule::code to Rule::noqa_code,
which is the code that --add-noqa will add to ignore a rule.
if_all_same(codes.values().cloned()).unwrap_or_default()
was quite unreadable because it wasn't obvious that codes.values() are
the prefixes. It's better to introduce another Map rather than having
Maps within Maps.
```console
❯ cargo run rule B017
Finished dev [unoptimized + debuginfo] target(s) in 0.13s
Running `target/debug/ruff rule B017`
no-assert-raises-exception
Code: B017 (flake8-bugbear)
### What it does
Checks for `self.assertRaises(Exception)`.
## Why is this bad?
`assertRaises(Exception)` can lead to your test passing even if the
code being tested is never executed due to a typo.
Either assert for a more specific exception (builtin or custom), use
`assertRaisesRegex` or the context manager form of `assertRaises`.
```
Martin Fischer
Charlie Marsh
Micha Reiser