[clang-tools-extra] [clang-tidy] Move part of bugprone-unhandled-code-paths to a new check readability-trivial-switch (PR #198237)

[Yanzuo Liu via cfe-commits]

================
@@ -83,8 +83,10 @@ Potentially Breaking Changes
                                      <clang-tidy/checks/cppcoreguidelines/pro-type-member-init>`
   ``hicpp-move-const-arg``           :doc:`performance-move-const-arg
                                      <clang-tidy/checks/performance/move-const-arg>`
-  ``hicpp-multiway-paths-covered``   :doc:`bugprone-unhandled-code-paths
-                                     <clang-tidy/checks/bugprone/unhandled-code-paths>`
+  ``hicpp-multiway-paths-covered``   | :doc:`bugprone-unhandled-code-paths
----------------
zwuis wrote:

```txt
| They are line blocks, which preserve line breaks.
| So that 'bugprone-unhandled-code-path' and 'readability-trivial-switch' are rendered in different lines.
```

Rendered as:

```txt
They are line blocks, which preserve line breaks.
So that 'bugprone-unhandled-code-path' and 'readability-trivial-switch' are rendered in different lines.
```

https://github.com/llvm/llvm-project/pull/198237