Select samples are not fully affected when changing themes

[YoannaIvanova]

Description

The Select samples don't reflect properly when changing themes, as seen in the dev demos.

Steps to reproduce

1. Open the Select topic and go to an example.
2. Apply Bootstrap, Fluent, and Indigo theme one after another.

Result

Only the text changes.

Expected result

The Select should have a border when changes to Bootstrap, Fluent, and Indigo theme.

[damyanpetev]

Likely the same issue that's affecting the Select in the paging when switching to Bootstrap? https://staging.infragistics.com/products/ignite-ui-angular/angular/components/grid/paging

[simeonoff]

We have to check if this is even reproducible since the issue is more than 2 years old.

[SisIvanova]

@dkamburov Everything looks fine in the samples repo. Therefore I think the problem comes from the theming widget or an old version of the samples used in the docfx.