Co-domain restriction for undeclared/axiom function and axioms for global lambdas

[etiennejf]

Co-domain restriction for undeclared/axiom function and axioms for global lambdas

Description

This PR addresses issue #28 and perform the following modifications:

• Smt Translation
  • Add co-domain restriction for undeclared class functions or automatized functions
  • Add congruence, extensionality and co-domain restrictions for global lambdas
• Test suite:
  • Add Issue29.lean to validate that co-domain restriction are properly considered for undeclared/axiom functions.

Closing tickets

Closes #414

Checklist

• All theorems valid for each formalization in CI
• All the specified lean file are properly considered when compiling and verifying the formalization
• Self review of the code has been done.
• Reviewer has been requested.
• Reviewer has performed the following tasks
  • Ensure that all the test cases are still valid
  • Ensure that each specified lean file is properly considered in the tool chain.