(core) Expanding widgets

Summary:
New icon to expand an active section and show it as a popup (just like raw data views).

"Show raw data" popup couldn't be reused (as it is basically a different page), so now
we have two kinds of popups that look the same.

1. Raw data popup - to show an alien section on a page (a section from a different view). This is used by "Show raw data" button, it is basically a different page that shows an arbitrary section.

2. Layout popup - a popup generated by Layout.ts that basically hides every other section and adds an overlay effect to itself.

Other changes
- Layout.js was migrated to typescript
- "Show raw data" menu item was converted to link

Test Plan: new tests

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3764

static/ui-icons/UI/Grow.svg

@@ -0,0 +1,6 @@
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+	<path d="M1.5 1.5L6.5 6.5" stroke="#929299" stroke-miterlimit="10" stroke-linecap="round" stroke-linejoin="round" />
+	<path d="M9.5 9.5L14.5 14.5" stroke="#929299" stroke-miterlimit="10" stroke-linecap="round" stroke-linejoin="round" />
+	<path d="M7.5 1.5H1.5V7.5" stroke="#929299" stroke-miterlimit="10" stroke-linecap="round" stroke-linejoin="round" />
+	<path d="M14.5 8.5V14.5H8.5" stroke="#929299" stroke-miterlimit="10" stroke-linecap="round" stroke-linejoin="round" />
+</svg>