[data-table] provide "fixHeader/fixColumn/fixRows" as "data-table"-parameters

[nimo23]

• [x] enhancement

• Framework7 Version: 2

Would be nice to have the following datatable-properties https://framework7.io/docs/data-table.html#data-table-parameters for "columns" and "rows" freezing:

• fixHeader: fixes the header while scrolling to bottom (like "Grouped with sticky titles" of https://framework7.io/docs/list-view.html#grouped-lists)
• fixColumns: fixes a list of columns while scrolling to right/left. For example, fixColumn={id1}: first column (with id1) is fixed while scrolling to right. For example, fixColumn={id1, id5}: there are 8 columns, id1 is the first column, id5 is at position 5. So when user scrolls to right, then first column is fixed and when scrolling to position after 5, then the two columns (id1, id5) are fixed and visible at the left side.
• fixRows: fixes a list of rows while scrolling to top/bottom For example, fixRows={id1, id5}: there are 8 columns, id1 is the first row, id5 is at position 5. So when user scrolls to bottom, then first column is fixed at the top and when scrolling to position after 5, then the two columns (id1, id5) are fixed and visible at the top after the header (which can also be fixed)