CMake: Fix WiX installer downgrades with versioned binaries

Since commit 5b9da05b (Windows: Embed version information into CMake
binaries, 2017-10-25, v3.11.0-rc1~411^2) our binaries have version
information that prevents a `.msi` downgrade from replacing them by
default.  Configure the re-install mode:

* a: reinstall all files regardless of version
* m: rewrite all per-machine registry entries
* u: rewrite all per-user registry entries
* s: reinstall shortcuts and icons

Fixes: #19006
11 jobs for <span class="ref-name">wix-cmake-downgrade-fix</span>
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