Incorrect position of the CSS classes in the `BitDatePicker` component style file

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All of the CSS classes which have not the -fluent suffix must come inside the root element class which consists of a -fluent suffix. For example, the .bit-dtp-field-grp class shown in the image below, has some styles that are for the Fluent design system like border: rem(1px) solid $Grey130;. So this class should be positioned inside the .bit-dtp-fluent class.