Improve CMake file

[OPNA2608]

• Install calls should be added for the built libraries & test binaries
• MSVC needs the _CRT_SECURE_NO_WARNINGS define set so it'll shut up about its "superior" secure function alternatives

Pretty easy, just need to find the time & boredom to actually do it.

[OPNA2608]

Fixed by 0dcf836a25b0da6a6ae2c6747896dc26afef3e35 and https://github.com/OPNA2608/libopenpmd/commit/c8624ba5fd048500ebfd4384f7ce7eb1b86ba47f.