version-14: Refactoring for perfs and maintainability

[beingeek]

Gitlab issue: https://git.phamos.eu/phamos/hr-department/-/work_items/12
Mattermost Thread: https://chat.phamos.eu/team-philipp/pl/4y6smeomt7ryxfjjep1mkpqbba

This PR implements extensive refactoring and cleanup in the HR-Addon’s workday processing functionality for version-14. Inconsistent Implementation of Workday Record Handling, listed below are the PR's to refactor in order to reduce redundancy, code cleanup, improving consistency and performance.

The main objectives of this PR include:

Key Changes:

• Workday & HR Settings Refactoring

  • Adjusted the HR-Addon settings logic to integrate more smoothly with the workday module.
  • Moved several utility functions into the core workday processing file to reduce code duplication.

• Field & Schema Cleanup

  • Removed deprecated or unused fields (e.g. in workday.json) to simplify the schema.
  • Raw SQL calls have been replaced with frappe.query_builder and frappe.get_cached_value, leading to more efficient and maintainable queries.

• Eliminated redundant columns and associated calculations in the Weekly Working Hours module.

• Enhanced Error Handling & Feedback

  • Updated error messages to include clickable links that direct users to the conflicting workday record—this change makes debugging and record resolution more efficient.
  • New notification features have been added to alert users if workday generation fails, including clearer error messages that help pinpoint conflicts.
  • Cleanup tasks include removing whitespace, commented-out code, and typos to enhance code readability.
  • Additional steps have been introduced to normalize workday data, ensuring consistency across the application.

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Related Pull Requests

• refactor/2-move-utils.py-to-workday.py #148: Refactoring to move utility functions into the workday module.
• refactor/3-move-hr_addon_settings.py-to-workday.py #149: Moving HR addon settings code into workday.py.
• refactor/4-move-anniversary-reminder-to-hr_addon_settings.py #150: Migrating the anniversary reminder functionality to HR addon settings.
• refactor/5-move-export_calendar-to-hr_addon_settings.py #151: Relocating export calendar logic into HR addon settings.
• refactor/6-move-custom_scripts-to-weekly_working_hours.py #152: Moving custom scripts functionality to Weekly Working Hours.
• refactor/7-move-list_view-to-weekly_working_hours #153: Consolidating the list view logic into Weekly Working Hours.
• refactor/8-change-add_custom_field_for_employee.py-patch-to-fixture #154: Patching the add_custom_field for employee fixtures.
• Refactor/12 refactoring workday controller #155: Refactoring the workday controller for better maintainability.
• refactor/9-use-frappe.query_builder-over-frappe.db.sql #156: Replacing raw SQL queries with frappe.query_builder.
• Refactor/21 workday normalization #164: Merging improvements for workday normalization.
• fix: bug in workday employee_checkins col "employee_checkin" #167: Finalizing workday normalization changes.
• feature/25-notification-for-workday-generation-failure #170: Removing redundant notification fixtures.