Easing the modification of mySQL user's credentials in the Installation_Test project

[aubertc]

In short Implement the DetermineSQLLogin routine that improves security and portability into the Installation_Test, and document it.

In more details:

• The DatabaseIO project file has a method that determines if LoginInfo.xml or LoginInfoTemplate.xml should be used to fetch the user credential. This has multiple benefits, the main one being that the user can easily insert their own SQL credential without risking to leak them.
• The same method should be implemented in the Installation_Test program.
• This method should also be more carefully documented:
  • [x] Improve the description at https://github.com/popbr/data-integration/tree/main/Project/Database-IO#login-information
  • [x] Comment the LoginInfo.xml file with a disclaimer ("Don't insert your information here, refer to for how to change the credentials"),
  • [x] Document this routine in the Installation_Test project as well.

[aubertc]

All of that was taken care of, and tested, during last week: https://github.com/popbr/data-integration/compare/7ce9d01..446a533

There was a discrepancy between the methods used in DatabaseIO and Installation_Test: maybe that should be resolved?