Hide symbols from shared libraries by default and support DLL creation

[ChrisThrasher]

https://gcc.gnu.org/wiki/Visibility

Hiding symbols by default from shared libraries has benefits you can read about above. Along with doing this we also ensure that DLLs are supported on Windows and thus make sure we provide 1st class support to all uses irrespective of their platform of choice.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (f2f9398) 98.65% compared to head (9dbb767) 98.65%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #122   +/-   ##
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  Coverage   98.65%   98.65%           
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  Files          11       11           
  Lines         223      223           
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  Hits          220      220           
  Misses          3        3           

Flag	Coverage Δ
humble	98.65% <ø> (ø)
rolling	98.65% <ø> (ø)

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[ChrisThrasher]

@traversaro Would you mind trying this out to see if it fixes your issues building DLLs? As for CMAKE_RUNTIME_OUTPUT_DIRECTORY I'm unsure if I'll hardcode that into the library but at least for the sake of testing you can specify that as a configuration parameter.

[traversaro]

Just tested on VS2022 with:

mamba create -n rsldev -c conda-forge -c robostack-staging eigen fmt ros-humble-rclcpp ros-humble-tl-expected ros-humble-tcb-span ros-humble-ament-cmake-ros clang-tools range-v3 vs2022_win-64 cmake ninja pkg-config
mamba activate rsldev
cd C:\src
git clone https://github.com/PickNikRobotics/RSL
cd RSL
git checkout hide_symbols
mkdir build
cd build
cmake
cmake -GNinja -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=C:\src\RSL\build\install -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=C:\src\RSL\build\bin -DRSL_BUILD_TESTING:BOOL=ON ..
ninja
ctest

and it works fine.