Don't split functionalities into mixins

[VitorLuizC]

Right now, all table functionalities are separated into mixins which handle everything, but DataTable component's template use some that mixin properties. It's hard to trace properties on component's template and the only way to fix it is merging them to component and split only helper functions.

Would be a solution, also, create DataTableRow and DataTableCol to handle style and to export them.

• Merge Sortable mixin to component;
• Merge Selectable mixin to component;
• Merge Alignable mixin to component;
• Create DataTableRow;
• Create DataTableCell;