Fix windows tests

[talregev]

Fix windows tests:

1. compile with ninja
2. Add fix for compilation in Visual Studio. This seems to be a weird issue with how size_t is interpreted since the multiple symbols defined error comes from additional declarations of std::map<Key, size_t>. This might be a bug in MSVC 16. from Fix Windows Tests borglab/gtsam#1553
3. GTSAM_EXPORT on functions.
4. GTSAM_EXPORT on nested structs / classes.

[talregev]

gtsamDebug.lib(gtsamDebug.dll) : error LNK2005: "public: unsigned __int64 __cdecl std::_Tree<class std::_Tmap_traits<unsigned __int64,unsigned __int64,struct std::less,class std::allocator<struct std::pair<unsigned __int64 const ,unsigned __int64> >,0> >::size(void)const " (?size@?$_Tree@V?$_Tmap_traits@_K_KU?$less@_K@std@@v?$allocator@U?$pair@$$CB_K_K@std@@@2@$0A@@std@@@std@@QEBA_KXZ) already defined in LPInitSolver.cpp.obj

[talregev]

testBasisFactors.cpp.obj : error LNK2019: unresolved external symbol "class Eigen::Matrix<double,-1,-1,0,-1,-1> __cdecl gtsam::kroneckerProductIdentity(unsigned __int64,class Eigen::Matrix<double,1,-1,1,1,-1> const &)" (?kroneckerProductIdentity@gtsam@@ya?AV?$Matrix@N$0?0$0?0$0A@$0?0$0?0@Eigen@@_KAEBV?$Matrix@N$00$0?0$00$00$0?0@3@@z) referenced in function "protected: void __cdecl gtsam::Basis::VectorDerivativeFunctor::calculateJacobian(void)" (?calculateJacobian@VectorDerivativeFunctor@?$Basis@VChebyshev2@gtsam@@@gtsam@@IEAAXXZ)

[talregev]

testChebyshev2.cpp.obj : error LNK2019: unresolved external symbol "public: static class gtsam::Pose3 __cdecl gtsam::Pose3::ChartAtOrigin::Retract(class Eigen::Matrix<double,6,1,0,6,1> const &,class gtsam::OptionalJacobian<6,6>)" (?Retract@ChartAtOrigin@Pose3@gtsam@@sa?AV23@AEBV?$Matrix@N$05$00$0A@$05$00@Eigen@@v?$OptionalJacobian@$05$05@3@@z) referenced in function "public: virtual void __cdecl Chebyshev2InterpolatePose3Test::run(class TestResult &)" (?run@Chebyshev2InterpolatePose3Test@@UEAAXAEAVTestResult@@@z)

[talregev]

testSignatureParser.cpp.obj : error LNK2019: unresolved external symbol "public: static class std::optional<class std::vector<class std::vector<double,class std::allocator >,class std::allocator<class std::vector<double,class std::allocator > > > > __cdecl gtsam::SignatureParser::Parse(class std::basic_string<char,struct std::char_traits,class std::allocator > const &)" (?Parse@SignatureParser@gtsam@@sa?AV?$optional@V?$vector@V?$vector@NV?$allocator@N@std@@@std@@v?$allocator@V?$vector@NV?$allocator@N@std@@@std@@@2@@std@@@std@@aebv?$basic_string@DU?$char_traits@D@std@@v?$allocator@D@2@@4@@z) referenced in function "public: virtual void __cdecl SimpleParserSimpleTest::run(class TestResult &)" (?run@SimpleParserSimpleTest@@UEAAXAEAVTestResult@@@z)

[talregev]

testOrdering.cpp.obj : error LNK2019: unresolved external symbol "public: class gtsam::Ordering & __cdecl gtsam::Ordering::operator+=(class std::vector<unsigned __int64,class std::allocator > &)" (??YOrdering@gtsam@@QEAAAEAV01@AEAV?$vector@_KV?$allocator@_K@std@@@std@@@z) referenced in function "public: virtual void __cdecl OrderingAppendVectorTest::run(class TestResult &)" (?run@OrderingAppendVectorTest@@UEAAXAEAVTestResult@@@z)

[talregev]

I don't know yet how to fix:
gtsamDebug.lib(gtsamDebug.dll) : error LNK2005: "public: class Eigen::Matrix<double,-1,1,0,-1,1> __cdecl gtsam::NoiseModelFactorN::evaluateError(class gtsam::Pose3 const &,class Eigen::Matrix<double,-1,-1,0,-1,-1> &)const " (?evaluateError@?$NoiseModelFactorN@VPose3@gtsam@@@gtsam@@qeba?AV?$Matrix@N$0?0$00$0A@$0?0$00@Eigen@@AEBVPose3@2@AEAV?$Matrix@N$0?0$0?0$0A@$0?0$0?0@4@@z) already defined in testImuFactor.cpp.obj

[talregev]

I don't know yet how to fix:
gtsamDebug.lib(gtsamDebug.dll) : error LNK2005: "public: class Eigen::Matrix<double,-1,1,0,-1,1> __cdecl gtsam::NoiseModelFactorN::evaluateError(class gtsam::Pose3 const &)const " (?evaluateError@?$NoiseModelFactorN@VPose3@gtsam@@@gtsam@@qeba?AV?$Matrix@N$0?0$00$0A@$0?0$00@Eigen@@AEBVPose3@2@@z) already defined in testImuFactor.cpp.obj

[talregev]

gtsamDebug.lib(gtsamDebug.dll) : error LNK2005: "public: __cdecl std::vector<unsigned __int64,class std::allocator >::vector<unsigned __int64,class std::allocator >(class std::initializer_list,class std::allocator const &)" (??0?$vector@_KV?$allocator@_K@std@@@std@@qeaa@V?$initializer_list@_K@1@AEBV?$allocator@_K@1@@z) already defined in testSymbolicConditional.cpp.obj