Serialization examples using CKKS

Addresses #229 (closed)

• Work in the style of the existing src/pke/simple-integers-serial.cpp

• A "server" and "client" split across 2 files. Sequentially:

  • The server encrypts data and sends necessary information to the client.

  • The client then does a series of additions, multiplications and rotations

  • Client also encrypts other data

  • Client sends data to the server to evaluate correctness of all the operations

TODO: All the parts are implemented in 1 file. Split it across 2 files with a central driver

Addresses #230 (closed)

• adds notes to the CKKS serialization examples to note that should users wish to run locally (or from individual files) that failures are to be expected unless they change their paths