[clang-tools-extra] create new clang-tidy check to add namespaces to symbol references (PR #70621)

[Piotr Zegar via cfe-commits]

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@@ -0,0 +1,22 @@
+// RUN: %check_clang_tidy %s readability-use-explicit-namespaces %t
+
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PiotrZSL wrote:

Add tests with:
- templates
- operators
- classes
- fixes
- ...

https://github.com/llvm/llvm-project/pull/70621