Add Module For Checking Atomic

[jungleraptor]

Some toolchains require explicitly linking against libatomic

If such linking is required, then this function sets the
value of result to "atomic". Otherwise it remains untouched.
This makes it so that the function only needs to be called once
per project.

It can be used as follows:

include(CheckAtomic)
check_cxx_needs_atomic(LINK_ATOMIC)
target_link_libraries(foo PRIVATE ${LINK_ATOMIC})
...
target_link_libraries(bar PRIVATE ${LINK_ATOMIC})

[sonarcloud]

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[jungleraptor]

@RReichert What are the advantages of a C based version?

I can still look into implementing that also.

[RReichert]

@RReichert What are the advantages of a C based version?

I can still look into implementing that also.

Just in case we want to use atomic in C programs, which we currently don't have a need for, so its not necessary.