refactor: restructure setup data and customizations to follow hms_tz …refactor: restructure customizations and setup data to follow hms_tz pattern

[LISACORNEL]

Summary

• Custom fields moved from utils/custom_field.json to numbered JSON files
  under patches/custom_fields/custom_fields_json/ — applied via
  create_custom_fields() API on every bench migrate
• Sales Order client script moved from Client Script DB record to physical
  public/js/sales_order.js loaded via doctype_js in hooks.py
• Role and Payment Term seed data moved to patches/setup_data/ as one-time
  patches registered in patches.txt
• Property setter infrastructure added under patches/property_setter/ —
  wired in after_migrate, ready for use when needed
• utils/ folder deleted — fully replaced by the above

Test plan

• bench migrate runs without errors
• All 31 custom fields present on Sales Order, Sales Invoice,
  Purchase Order Item, Purchase Invoice Item, Supplier
• Sales Order form auto-populates from Plot Application via doctype_js
• Role "Land Acquisition Approver" exists
• Payment Terms "Advance" and "Balance" exist
• No Client Script DB records for LandMS