[data grid] Remove the editing experimental features and make them enabled by default

[joserodolfofreitas]

Summary

Breaking change for v6.
For more context: #3287

mui-x/packages/grid/x-data-grid/src/models/props/DataGridProps.ts

Lines 34 to 41 in b778028

	/**
	* Will be part of the premium-plan when fully ready.
	*/
	preventCommitWhileValidating: boolean;
	/**
	* Enables the new API for cell editing and row editing.
	*/
	newEditingApi: boolean;