STCOM-929 NavListSection should accept a tag prop (#1716)
STCOM-929 NavListSection should accept a tag prop (#1716)

In the scope of fixing some a11y issues in 
[UIU-2037](https://issues.folio.org/browse/UIU-2037), we need to 
replace a `<div>` for General, Fee/Fine, Patron blocks with an 
`<h3>`. So, in NavListSection I added tag prop to Headline component. 

Ref: https://issues.folio.org/browse/UIU-2037
Ref: https://issues.folio.org/browse/STCOM-929

folio-org/stripes-components,folio-org/stripes-components