Separate http into a completely separate folder (aiming to make a lib and to be installable by Conan)

[nobugs-hare]

To be easily usable, we have to provide package manager (in our case - Conan).

Our principles of working with Conan:

• each package consists of a COMPLETELY SEPARATE set of IMMUTABLE files (this is EXTREMELY IMPORTANT)
• each package is either (a) header-only, OR (b) is a static library (in CMake sense)
• for each deployment scenario, we have a minimal package with "core" in its name ("core" includes the absolute minimum - but including memory safety, exceptions/asserts, and logging); in some cases, the same Conan may also include some other APIs (those which are too tightly coupled to separate at lib level).
  • for "server-side deployment" scenario, minimal package is "net-core" package.
• each of non-core packages MUST include a special file with "allowed APIs" for static checker; this allows, say, to have 'logging' package which uses files but does NOT expose file API to the next-level package, reducing dependency levels.

http is a good first example to show "how do we separate our packages". Make sure that ALL internal logging/tracing/asserting refers to 'nodecpp.http' module