Tksheet

Added:
- Progress bars

Fixed:
- Fix resizing cursor appearing at start of header/index and causing issues if clicked

Fixed:
- Fix add columns/add rows not inserting at correct index when index is larger than row or data len
- Fix add columns/add rows not undoing/redoing added heights/widths respectively
- Fix add columns/add rows regression

Added:
- Add functions to address [227](https://github.com/ragardner/tksheet/issues/227):
- `get_column_text_width`
- `get_row_text_height`
- `visible_columns` - `property`
- `visible_rows` - `property`

Changed:
- Internal parameter names:
- `only_set_if_too_small` -> ` only_if_too_small`
- Internal functions:
- `get_visible_rows`, `get_visible_columns` -> `visible_text_rows`, `visible_text_columns`, also changed to properties `property`
- Internal function parameters:
- `set_col_width`
- `set_row_height`

Fixed:
- Regression since `7.2.0`: selection box borders not showing for rows/columns

Changed:
- Slightly reduced minimum row height since `7.2.0` change

Fixed:
- Cells in index/header not having correct colors when columns/rows were selected
- [226](https://github.com/ragardner/tksheet/issues/226)

Changed:
- A somewhat major change which warranted a significant version bump - **the minimum row height has increased slightly** to better accodomate the pipe character `|`

Fixed:
- Error on paste into empty sheet with `expand_sheet_if_paste_too_big`
- Data shape not being correct upon inserting a single column or row into an empty sheet
- Potential for `insert_columns()` to cause issues if provided columns are longer than current number of sheet rows
- [225](https://github.com/ragardner/tksheet/issues/225) Insert columns and insert rows not inserting blank cells into header/row index, issue seen with either:
- Right clicking and using the in-built insert functionality
- Using the `Sheet()` functions with an `int` for first parameter
- Wrong sheet dimensions caused by a paste which expands the sheet
- Wrong new selection box dimensions after paste which expands the sheet
- `set_options()` with `table_font=` not working

Changed:
- `expand_sheet_if_paste_too_big` replaced by `paste_can_expand_x` and `paste_can_expand_y`. To avoid compatibility issues using `expand_sheet_if_paste_too_big` will set both new options

Improved:
- Additional protection against issue [224](https://github.com/ragardner/tksheet/issues/224) but with `auto_resize_row_index="empty"` which is the default setting