Fix build of meataxe extension with meson

[antonio-rojas]

meataxe is not a library, the library is called mtx and is already searched for

[antonio-rojas]

tdlib and mcqd are also not found because they are header-only, so find_library doesn't work.

[github-actions]

Documentation preview for this PR (built with commit 46892d4; changes) is ready! 🎉
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[tobiasdiez]

Thanks!

[tobiasdiez]

tdlib and mcqd are also not found because they are header-only, so find_library doesn't work.

They also don't seem to provide pkg-config info. So just using cc.has_header to check for the required headers, and if then set the dependency object to disabler() if not found?

[antonio-rojas]

tdlib and mcqd are also not found because they are header-only, so find_library doesn't work.

They also don't seem to provide pkg-config info. So just using cc.has_header to check for the required headers, and if then set the dependency object to disabler() if not found?

Done in #38984

[antonio-rojas]

Setting back to positive review, it was a simple rebase