fix: allign patterns check logic with Github ones

[AlvaroGG0]

The current verification of patterns does not follow the same logic as Github's when they do not start with /, which causes Codeowners to mismatch in these cases.

From Github documentation:

# In this example, @octocat owns any file in an apps directory
# anywhere in your repository.
apps/ @octocat

Changes made:

• Concatenate **/ at the beginning of patterns in case they don't start with / to follow the same logic.
• A / is concatenated at the beginning of each changedFile string to make the minimatch function work well on those patterns with a / at the beginning.
• Modify required approvals logging from "Required codeowners: {"$CODEOWNER":false}" to "Required codeowners: $CODEOWNER" as it can lead to confusion

[skymoore]

@AlvaroGG0 Looks good to me, thank you for the contribution!

[skymoore]

@AlvaroGG0 https://github.com/skymoore/required-approvals/releases/tag/v4.2.2

[skymoore]

@AlvaroGG0 I invited you as a collaborator to the repository. It seems you are using this action a lot more than I am at the moment. Would appreciate your help here.