Fix deprecations + updates

Summary

Resolves

• #95 (closed)
• #93 (closed)
• #89 (closed)
• #92 (closed)
• #86 (closed)
• #72 (closed)
• #70 (closed)

Focus

• Updating to Debian 12 made creating a venv in the Dockerfile necessary
• clang-format-11->clang-format-16
• no more deprecation warnings for inheriting from std::iterator
• boost::string_file was replaced by copying the implementation from boost

Test Environment

How to set up a test environment for manual testing?

Check List for the Author

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  • Intent of new code
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Check List for the Reviewer

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• All automated tests pass
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• Appropriate user and developer documentation (or not necessary)
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.docker/Dockerfile

@@ -2,7 +2,8 @@ FROM debian:bookworm
 
 RUN apt-get update
 RUN apt-get install -y cmake
-RUN apt-get install -y lcov
+# iwyu is not a strict dependency here, but in the cppinttests.
+RUN apt-get install -y lcov iwyu
 RUN apt-get install -y doxygen graphviz
 RUN apt-get install -y clang-format-16 clang-tidy-16
 RUN apt-get install -y python3-pip python3-venv