Cpp v2

[pedropgusmao]

Final tests with the CPP implementation

[scylj1]

Libtorch example finished

[tanertopal]

@scylj1 Thank you again for this great work. A few todo's as discussed previously:

• [ ] Add client code for secure connection which was merged here: #844 also we can think of adding this as a subsequent PR if it increases complexity too much. Beware that there where some additional PR's after #844 so ideally checkout the code in main.
• [ ] Use clang-format-10 for C++ code. It is currently used for the protobufs. See here
• [ ] Add the default copyright header to all files in src as can be seen here

I will do a code review sometime today and give a bit more feedback.

[pedropgusmao]

I believe we do not have a get_properties() implementation yet.