Is your feature request related to a problem? Please describe.

When is used with a different theme a type input needs to be set to the corresponding theme to change the structure of the component in order to apply the theme correctly. It appears that there is no easy way to infer the type from the theme. In most cases the user can set the type himself on the component. Components however that use the internally don’t have a way for the user to set the type, which means that there’s no way out of the box to style them according to the applied theme.

Some such components:

1. Grid Editors – the editors for edit functionality are by default input-groups/date-picker. Unless the user templates each cell editor and sets the type input the editors cannot be styled according to the theme.
2. Date Picker – uses input-group for both default templates. Does not appear to be a way to set type.
3. Time Picker – same as Date Picker.
4. Combo – this one has its own type @input that is then set to the main input, however there is also a search input in the drop-down (which is enabled when filterable) that does not seem to be settable based on the theme.

Describe the solution you'd like

Expose some way to set the Input Group type globally so that components that use it internally inherit it from the parent or use the globally set one (maybe something similar to the DisplayDensity implementation or a global service that sets the type).

Describe alternatives you've considered

Additional context

Related to: IgniteUI/igniteui-angular-samples#1757
Once we have a way to set this globally we can apply it in the Samples Browser.