(ci): add static analysis

Description

We spend way too much time in review to detect mistakes that could be detected by a good static analysis tool. Sheldon has a hook to launch cppcheck but we never enabled it on the ci, apparently because it was very slow.

Proposal

• Reevaluate cppcheck run on the ci
• Evaluate clang-tidy
• Evaluate gcc11 static analysis tool

Evaluation

Clang-tidy

• Works with a program database: requires building sight

• CMake provides a variable to enable checks:

  set(CMAKE_CXX_CLANG_TIDY ${CLANG_TIDY};--header-filter=.*;--checks=*,-llvm-header-guard,-llvmlibc-*,-fuchsia-*,-altera-struct-pack-align,-bugprone-macro-parentheses;--use-color)

  --checks=* -> enable all checks --checks=-<...> -> disable checks

• Provides an "auto-fix" mode, but is rather unusable since too much "fixes" break the code. Since CMake variable is global, there is no way to disable it easily for a part of sight...