add base support for exporting objects and classes in node_loader#1

[rxbryan]

Description

This PR is the first in a series, that split https://github.com/metacall/core/pull/343 into moderately sized commits.

Files

• bootstrap.js
• node_loader_impl.cpp

Fixes #(132)

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update
• [ ] Documentation update

Checklist:

• [x] I have performed a self-review of my own code.
• [ ] I have commented my code, particularly in hard-to-understand areas.
• [ ] I have made corresponding changes to the documentation.
• [ ] My changes generate no new warnings.
• [ ] I have added tests/screenshots (if any) that prove my fix is effective or that my feature works.
• [ ] I have tested the tests implicated (if any) by my own code and they pass (make test or ctest -VV -R <test-name>).
• [ ] If my change is significant or breaking, I have passed all tests with ./docker-compose.sh test &> output and attached the output.
• [ ] I have tested my code with OPTION_BUILD_SANITIZER or ./docker-compose.sh test-sanitizer &> output and OPTION_TEST_MEMORYCHECK.
• [ ] I have tested my code with OPTION_BUILD_THREAD_SANITIZER or ./docker-compose.sh test-thread-sanitizer &> output.
• [ ] I have tested with Helgrind in case my code works with threading.
• [ ] I have run make clang-format in order to format my code and my code follows the style guidelines.

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