Evaluate stronger event typing for custom elements

[rajsite]

🧹 Tech Debt

We override HTMLElementTagNameMap to add definitions for our custom elements like:

declare global {
    interface HTMLElementTagNameMap {
        'nimble-select': Select;
    }
}

It seems possible to also override definitions in HTMLElementEventMap like:

declare global {
    interface HTMLElementEventMap {
        'filter-input': CustomEvent<SelectFilterInputEventDetail>;
    }
}

Which would result in lines like the following having strong typing without any casts:

selectElement.addEventListener('filter-input', evt => evt.detail.filterText);

We should evaluate:

• Is this a good idea / is there precedence in other custom element libraries?
• What happens for multiple definitions of the same event name?