Fix/duplicate import error throwing

[ermijeremy]

Related Issue

Closes #154

Summary

Prevent duplicate import! loads by tracking absolute import paths and ignoring duplicate imports.

What Changed

• import! now normalizes every import to an absolute path.
  • .py imports resolve to an absolute path and import the Python module.
  • Other imports resolve to an absolute .metta path and load the MeTTa file.
• Each imported absolute path is stored in a dynamic predicate imported_file/1.
• If the same absolute path is imported again, it will be ignored`.

Why This Fixes the Issue

Previously, repeated import! calls could reload the same file multiple times, causing duplicated definitions and inconsistent behavior.
By normalizing to a canonical absolute filename and recording it in imported_file/1, any subsequent import of the same file is detected and rejected reliably.

How It Works (Mechanics)

1. Resolve File to an absolute path.
2. Check imported_file(AbsPath):
   • If found → ignore the duplicated import.
   • If not → load file and assertz(imported_file(AbsPath)).

Tests

• Added minimal test that imports the same file twice in one MeTTa file and asserts an exception is raised.

[patham9]

Thank you very much!
Only: there should be no import error being generated.
Often libraries depend on same core libraries, it is normal.
It only should ensure that no library is loaded twice.

[ermijeremy]

Thank you very much! Only: there should be no import error being generated. Often libraries depend on same core libraries, it is normal. It only should ensure that no library is loaded twice.

@patham9 it no longer throws error instead if a duplicate import is found it just ignores it
-> true