Fix ruby 2.7 warnings on core

[stefano-sarioli]

Description

Ruby 2.7 enabled some new warnings on how you can pass default and hash parameters to a function.
This PR fixes the warning inside our core code, the remaining on the core are coming from some external gems, I'm going to open issues on the affected gems about this.

I thought that doing one component at a time, instead of all the code at once, can create enable reviews and avoid some small errors that can be missed when doing repetitive tasks like this one.

Let me know what you think about this.

Checklist:

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message
• I have updated Guides and README accordingly to this change (if needed)
• I have added tests to cover this change (if needed)
• I have attached screenshots to this PR for visual changes (if needed)

[spaghetticode]

@stefano-sarioli thank you!

[aldesantis]

Thanks @stefano-sarioli!