feat: Add groupBy as a new feature in repository

[gabrielmpetrescu]

No description provided.

[what-the-diff]

PR Summary

• Introduction of Group By Feature
  The system now has a feature that allows users to group results based on specific columns. For example, if the data has columns for 'Name', 'Age', and 'Location', users can group the results by 'Location' to better understand the distribution of data.

• Group By Parameter Retrieval Function
  A new method has been added in code for the system to collect and understand 'group by' instructions from the user's input.

• Storage of Grouping Information
  A space in the system memory (a static property) named $groupBy is defined to keep the list of fields that can be targeted for the grouping function.

• Grouping Logic
  The pull request introduces methods in code to manage the user's 'group by' instructions. The introduced method, applyGroupBy, interprets the user's instructions and executes the group by operations.

• Error Handling for Grouping
  The system has enhanced its error handling mechanism in the case of an attempted grouping by an invalid or ungroupable column.

• Testing of New Feature
  This change also accompanies new test scenarios. The test scenarios ensure the successful execution of grouping as well as the proper management of invalid grouping commands.

[binaryk]

Some psalm issues.

[binaryk]

Thank you!