feat(`@vtmn/svelte`): dispatch missing events on `VtmnInput` + export ref on `VtmnIcon`

[Tlahey]

Changes description

Dispatch missing events on VtmnInput component

• on:keyup
• on:keydown
• on:keypress

Add ref on VtmnIcon

Context

Checklist

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• [x] Check your code additions will fail neither code linting checks.
• [x] I have reviewed the submitted code.
• [x] I have tested on related showcases.
• [x] If it includes design changes, please ask for a review design-system-core-team-design GitHub team.

Does this introduce a breaking change?

• No

Other information