[data grid] Refactor GridFilterItem properties

[joserodolfofreitas]

Summary

Breaking change for v6.
For more context: #3287

• Rename GridFilterItem['columnField'] -> GridFilterItem['field']
  

  mui-x/packages/grid/x-data-grid/src/models/gridFilterItem.ts

  Line 13 in b778028

  columnField: string;

• Rename GridFilterItem['operatorValue'] -> GridFilterItem['operator']
  

  mui-x/packages/grid/x-data-grid/src/models/gridFilterItem.ts

  Line 23 in b778028

  operatorValue?: string;

  Context: [DataGrid] Fix date operators not working with date-time values #1722 (comment)

• Make GridFilterItem['operatorValue'] (renamed 'operator') required

  Context: [DataGrid] Improve the invalid sortModel and filterModel warnings #3671 (comment)
  see this comment]([DataGrid] Improve the invalid sortModel and filterModel warnings #3671 (comment))

Motivation