feat(ui5-shellbar): branding slot introduced

[yanaminkova]

The branding slot has been introduced to the ui5-shellbar component.
Additionally, a new component called ui5-shellbar-branding has been added. This component combines a logo and a title, with the ability to open links. Its primary purpose is to be used within the branding slot, replacing the default primary title and logo of the ui5-shellbar.

The branding slot and its content take higher priority. As a result, if both the branding and the primary title + logo slot are used, only the ui5-shellbar-branding will be displayed.

[dobrinyonkov]

Already looks good, just a few stuff to talk about:

• dedicated ShellBarBranding.cy.tsx file for the branding related tests?
• also, more tests for the ShellBarBranding logic like properties, acc, slots, ect?
• update all samples where shellbar is used with the new slot?

I know we talked to have the "primaryTitle/brandingTitle" as a slot, but now I'm rethinking, what if someone wants to have custom title later on, perhaps it could be better to "reserve" the slot for that and use a property now. We can have a call about this and decide.

FYI, we decided to go with the "branding" name, so ui5-shellbar-branding and branding slot are OK.

[dobrinyonkov]

This whole link case seems to be covered by the branding component, perhaps, let's also check the "old" case where a href is not provided. We may need to render an element with a button role, instead of anchor, to have accessibility compliant html strucure.

[dobrinyonkov]

The logo is no longer an interactive area, role link does not make sense. Seems to me that it needs to be img or presentation (decorative). This need to be checked with accessibility spec.

[yanaminkova]

The value returned by this getter is assigned to the anchor element, not to the logo itself. I might rename the getter to better reflect what it's used for.