CLN TST: Refactor `Styler.bar` tests through parametrisation
`Styler.bar` tests are refactored to avoid code duplication and enhance the testing process to cover a wider array of scenarios with simpler code.

Summary of removed tests and their replacement coverage:

Original Test | Replaced By | Parameters |
--- | --- | --- |
test_bar_align_left | test_align_positive_cases <br> test_numerics <br> test_colors_mixed | align=left |
test_bar_align_left_0points | test_align_axis | axis=[index,columns] <br> align=left |
test_bar_align_mid_pos_and_neg | test_align_mixed_cases <br> test_colors_mixed | align=mid |
test_bar_align_mid_all_pos | test_align_positive_cases | align=mid |
test_bar_align_mid_all_neg | test_align_negative_cases | align=mid |
test_bar_align_zero_pos_and_neg | test_align_mixed_cases <br> test_colors_mixed | align=zero |
test_bar_align_left_axis_none | test_align_axis | align=left <br> axis=None |
test_bar_align_zero_axis_none | test_align_axis | align=zero <br> axis=None |
test_bar_align_mid_axis_none | test_align_axis | align=mid <br> axis=None |