DataGrid: Fix Localization FilterMethods

[panmona]

Description

• Remove hardcoded "Filter" and "Clear Filter" localizations
• Add custom localizers for GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual
• Fix localization resource name of GreaterThanOrEqual and LessThanOrEqual
• Add FilterMode to DataGrid demo for easier testing

Related to #5468

How Has This Been Tested?

• Tested in Material Datagrid Demo

Types of changes

• [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 not to work as expected)

Checklist:

• [x] The PR is submitted to the correct branch (master for dev, rel-1.x for maintenance).
• [x] My code follows the code style of this project.
• [ ] I've added relevant tests. -> only tested with the Demo. Not sure how else this can be tested.