feat(Parameters): Dump integers with type attribute

[Hipska]

Base information

Question	Answer
Related to a SourceForge thread / Another PR / Combodo ticket?	N/A
Type of change?	Enhancement

Objective

The dump should keep/store the type attributes from the original parameters file.

Proposed solution

Add type="int" attribute when the value is an integer.

Checklist before requesting a review

• I have performed a self-review of my code, and that it's compliant with Combodo's guidelines
• I have tested all changes I made on an iTop instance
• I have added a unit test, otherwise I have explained why I couldn't
• I have made sure the PR is clear and detailled enough so anyone can understand the real purpose without digging in the code