Image editor UI refined; grid span defaults unsettable with viewport states

Changelog

Enhancements

Block Library

• Hide Cover overlay controls for viewport states. (78763)
• Hide image dimension tools when a state is selected. (78670)

Media

• Image cropper: Round zoom control values and display as percentages. (78757)
• Media Editor: Remove resize handles toggle from crop panel. (78758)

Bug Fixes

Block Editor

• Unset grid span defaults with viewport states enabled. (78709)

Accessibility

Post Editor

• Image Editor: Focus return after closing image crop modal. (78711)

Experiments

Media

• Media Editor Modal: Try placing the save and cancel buttons in the footer. (78708)

Tools

Build Tooling

• Update browserslist. (78840)

Testing

• e2e-test-utils-playwright: Add src to published NPM files. (78847)
• Tests: Temporarily disable REST index output-format assertions pending Core fix. (78788)