[card] Add String title/subtitle API

[ugur-vaadin]

Describe your motivation

It is necessary to implement the Flow component counterpart for the web component issue.

Describe the solution you'd like

Add the following for the Card component:

• void setTitle(String title)
• void setTitle(String title, Integer headingLevel)
• String getTitleAsText() (similar to LoginOverlay)

Describe alternatives you've considered

No response

Additional context

No response

[jouni]

Someone raised a concern about using “title”, since that could be confused with the native HTML title attribute. Should we consider changing “title” and “subtitle” to something else, like “heading” and "subheading”?

[ugur-vaadin]

What do you think @rolfsmeds ?

[rolfsmeds]

Ah, indeed, we had the same issue with Dialog, and IIRC it's not just about risk of confusion but as browsers (still!) show the title attribute as tooltips, Cards would always have tooltips, which we certainly don't want.

For Dialog, we somehow ended up with header-title, but Dashboard Widgets have widget-title.

So for consistency with those, I suppose card-title (and sub-title) would make sense?