fix(ui5-input): fix scrolling item into view (#1848)

The scroll container should be awaited before we use it. Additionally, we use the step constant in the "isIteminView" method to avoid half visible items, because previously the input used to scroll if the item is entirely out of view (60 is the maximum height of a standard list item).

FIXES: #1847

packages/main/src/features/InputSuggestions.js

@@ -280,12 +280,13 @@ class Suggestions {
 		const rectInput = this._getComponent().getDomRef().getBoundingClientRect();
 		const windowHeight = (window.innerHeight || document.documentElement.clientHeight);
 
-		return (rectItem.top <= windowHeight) && (rectItem.top >= rectInput.top);
+		return (rectItem.top + Suggestions.SCROLL_STEP <= windowHeight) && (rectItem.top >= rectInput.top);
 	}
 
-	_scrollItemIntoView(item) {
-		const pos = item.getDomRef().offsetTop - Suggestions.SCROLL_STEP;
-		this._getScrollContainer().scrollTop = pos;
+	async _scrollItemIntoView(item) {
+		const pos = item.getDomRef().offsetTop;
+		const scrollContainer = await this._getScrollContainer();
+		scrollContainer.scrollTop = pos;
 	}
 
 	async _getScrollContainer() {
@@ -338,7 +339,7 @@ class Suggestions {
 	}
 }
 
-Suggestions.SCROLL_STEP = 48;
+Suggestions.SCROLL_STEP = 60;
 
 // The List and Popover components would be rendered
 // by the issuer component`s template.