[clang-tools-extra] [clang-tidy] Add a new check 'performance-string-view-conversions' (PR #174288)

[Victor Chernyakin via cfe-commits]

================
@@ -0,0 +1,83 @@
+// RUN: %check_clang_tidy -std=c++17 %s performance-string-view-conversions %t -- \
----------------
localspook wrote:

```suggestion
// RUN: %check_clang_tidy -std=c++17-or-later %s performance-string-view-conversions %t -- \
```

https://github.com/llvm/llvm-project/pull/174288