CMake: migrates changes for Levante to AWIESM 2.1 branch

[pgierz]

Includes changes to the build environment discussed in #336 for the AWI-ESM version of FESOM 2.1. I would please ask @hegish to check if this makes sense in the CMake world and @mandresm or @JanStreffing if it mirrors what you needed to do for AWI-CM3

[pgierz]

This PR also includes changes to make the tests run correctly. The failure in the testing suite is an in-complete separation of the iceberg code, and should probably be looked at by @ackerlar.

[JanStreffing]

Are we using DR_HOOK in FESOM2 now? DR_HOOK is the IFS internal debug program. See: https://confluence.ecmwf.int/download/attachments/19661682/drhook.pdf?version=1&modificationDate=1443002579511&api=v2

If we don't use it, we should not set any flag for it here.

[pgierz]

To my knowledge we are not, I just copied over from Miguel.

So then:

Suggested change

export DR_HOOK=1

[hegish]

Hey @pgierz, I did not spot anything while skimming through. But there are many changes. Anything special I should look out for?

[pgierz]

Hi @hegish, no, just a quick check if none of the CMakeLists look as if they are out of place. So, if you give a thumbs up, I will assume nothing is fishy.

In that case, there are still two changes needed, one @JanStreffing made me aware of, which I will take care after my holiday, and then @ackerlar still needs to put proper switches around his iceberg code. Currently, if the iceberg code is turned off, FESOM will not compile. Provisionally, I will just hard-wire it to be turned on.