Refactor/edit league dialog

[rbharath99]

Description

This PR refactors the edit league dialog for the gamification feature. Previously it was relying on the LeagueGameBloc but now it has its own bloc to handle the state:

• A new bloc called EditRulesBloc which handles the editing of a league
• Removed the EditLeagueEvent from the LeagueGameBloc since it is not needed anymore
• Significantly reduced the size of the widget tree. Each component is separated into its own Widget
• Handled form validation when the user confirms the editing of a league. For example, if a field is empty the user won't be able to update the rules

Fixes Jira Ticket #

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Is this a UI Change? If so please include screenshot of before and after states below

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have assigned 2 reviewers to check my work
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules