[#1997] Build system driver

[krendelhoff2]

Description

This PR presents the new build system.
The legacy build system was removed.
Object files related code is not included in this PR.
If it will be decided to include them into release, I'll provide related changes in the next PR.
This PR assumes we do not use registry anymore.
On the high level build process is more or less the same as before.

Stage 1:

1. File gets preprocessed.
2. Its compilation is driven up to Ast_core.
3. Its dependencies gets extracted.
   3.1. For jsligo, filepaths from import declarations are taken.
   3.2. For cameligo, references to modules which are not in the scope is considered a dependency.
4. Dependency information is getting resolved into file path.
   4.1. It's straightforward for jsligo.
   4.2. For cameligo, please see this comment.

Stage 2:

Compilation continues until reaches target AST.

Stage 3:

1. All the compiled AST gets aggregated into one in the correct order.
2. For cameligo, module aliases are added, because actual module names are different from the module paths they were resolved from.

#import preprocessor directive gets ignored. !3274 should be merged for proper warning.