Supporting other date patterns

[thegooman]

Describe the new feature being added The current date input editor only accepts dates formatted as: YYYY-MM-DD. Other patterns should be supported as well: MM-DD-YYYY.

How will this feature improve this extension This feature will make editing dates more flexible.

Describe alternatives you've considered N/A

Additional context Look into the pattern field for the HTML date input element. Also look at celleditor.ts in the Lumino Datagrid for the current input element being used.