Add in CI and document workaround for macOS/Homebrew Gazebo/tbb failures

[traversaro]

Workaround for #753 taken from osrf/homebrew-simulation#1486 (comment)

[traversaro]

This fixes the failures, except for LatestReleases that it still failing for:

2021-05-28T23:18:23.3204400Z /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -DBOOST_ALL_NO_LIB -DBOOST_FILESYSTEM_DYN_LINK -DBOOST_SYSTEM_DYN_LINK -Dblocktestcore_EXPORTS -Isrc/blocktestcore/blocktestcore_autogen/include -I/Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore -I/Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/extern/pugixml -isystem /usr/local/include -Wall -Wextra -O3 -DNDEBUG -isysroot /Applications/Xcode_12.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk -mmacosx-version-min=10.15 -fPIC -std=gnu++17 -MD -MT src/blocktestcore/CMakeFiles/blocktestcore.dir/libraryLoader.cpp.o -MF src/blocktestcore/CMakeFiles/blocktestcore.dir/libraryLoader.cpp.o.d -o src/blocktestcore/CMakeFiles/blocktestcore.dir/libraryLoader.cpp.o -c /Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore/libraryLoader.cpp
2021-05-28T23:18:23.3366980Z /Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore/libraryLoader.cpp:79:65: error: no member named 'import' in namespace 'boost::dll'
2021-05-28T23:18:23.3624130Z             boost::function<funcptr> stopFunction = boost::dll::import<funcptr>(
2021-05-28T23:18:23.3725670Z                                                     ~~~~~~~~~~~~^
2021-05-28T23:18:23.3828570Z /Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore/libraryLoader.cpp:79:72: error: unexpected type name 'funcptr': expected expression
2021-05-28T23:18:23.3930900Z             boost::function<funcptr> stopFunction = boost::dll::import<funcptr>(
2021-05-28T23:18:23.4032230Z                                                                        ^
2021-05-28T23:18:23.4135310Z /Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore/libraryLoader.cpp:80:17: warning: expression result unused [-Wunused-value]
2021-05-28T23:18:23.4237390Z                 libraryPath,
2021-05-28T23:18:23.4338680Z                 ^~~~~~~~~~~
2021-05-28T23:18:23.4441360Z /Users/runner/work/robotology-superbuild/robotology-superbuild/src/blocktestcore/src/blocktestcore/libraryLoader.cpp:81:17: warning: expression result unused [-W

However, even if this fixes the failures, I see no point in merging this unless we also update the user documentation, as otherwise CI would work fine, but the users would experience the exact failure.

[traversaro]

Let's get this documented at least for 2021.05 . For the next future I think as soon as the few macOS users inside IIT migrate to conda, I think we should re-evaluate our Homebrew level of support, given the amount of effort and mantainance that it requires (see https://github.com/robotology/robotology-superbuild/issues?q=is%3Aissue+homebrew+is%3Aclosed and all the times that CI was broken due to Homebrew related problems, while macOS/conda continued to work).

[traversaro]

Let's get this documented at least for 2021.05 .

Done in f0e3374 . The PR is ready for review.

[traversaro]

This fixes the failures, except for LatestReleases that it still failing for:

This was fixed by the new release of blocktest and 4ff3a61, let's see if now the CI is happy.