Remove outdated classes and selectors

[TeyaVes]

• [ ] Calendar- Remove outdate calendar navigation classes: k-nav-prev, k-nav-next, .k-prev-view, .k-next-view, k-nav-today, k-nav-fast once they are replaced in all products.
• [ ] Pager - Remove k-pager-wrap once it's replaced with k-pager in all products
• [ ] Stepper - remove k-step-focus
• [ ] Panelbar- remove k-state-expanded
• [ ] Scheduler- remove styles for k-nav-current anchor once it's replaced with flat button, k-sm-date-format and k-lg-date-format, k-y-date-format, k-m-date-format
• [ ] Grid - remove k-grouping-header-flex class once chiplist is added instead of k-indicator-container
• [ ] Grid - remove k-header-column-menu
• [ ] Upload - remove outdated styles and selectors for icons
• [ ] Grid - remove styles for icons .k-i-sort-asc-sm, .k-i-sort-desc-sm
• [ ] Grid - remove k-icon-sort-* classes and leave only .k-sort-icon selector after Grid High density is merged