[Core] Remove unused headers

The compilation of a PCB is part of the critical path for the creation of a
PCB, thus C++ IOStreams should be avoided. Indeed this support is known to
be one of the main responsible for compilation time.

Signed-off-by: Patrick Bellasi <derkling@gmail.com>
[Product] Switch to usage of pre-compiled header

The usage of pre-compiled headers, whicb are generated at core build time
is yet another update in the direction to reduce compilation time at minimum.

Signed-off-by: Patrick Bellasi <derkling@gmail.com>