fix(ui5-multi-input): expand tokenizer on focus in

[ndeshev]

fixes: #13179

[ui5-webcomponents-bot]

🧹 Preview deployment cleaned up: https://pr-13191--ui5-webcomponents.netlify.app

[Vonahz]

I noticed that when Multiinput is in readonly state tokenizer will expand when try to click the input (multiinput gets focus). Before it was expanded only if tokenizer is focused.
Not sure if this is desired. Couldn't find any specifics in the spec.

[ndeshev]

I noticed that when Multiinput is in readonly state tokenizer will expand when try to click the input (multiinput gets focus). Before it was expanded only if tokenizer is focused. Not sure if this is desired. Couldn't find any specifics in the spec.

Yes, the Tokenizer should expand on input focus.