(core) Form kanban tasks

Summary:
- Open all links in a new tab
- Excluding not filled columns (to fix trigger formulas)
- Fixed Ref/RefList submission
- Removing redundant type definitions for Box
- Adding header menu item
- Default empty values in select control

Test Plan: Updated

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D4166

static/ui-icons/UI/Headband.svg

@@ -0,0 +1,10 @@
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<g clip-path="url(#clip0_1061_7585)">
+<path d="M14 16L8 11L2 16V0H14V16Z" fill="black"/>
+</g>
+<defs>
+<clipPath id="clip0_1061_7585">
+<rect width="16" height="16" fill="white"/>
+</clipPath>
+</defs>
+</svg>