Resolve #3447257 "Make the sidebar resizable"

Closes #3447257

added 16 commits

• 2496116a...d317333d - 15 commits from branch project:4.0.x
• e1ea0c6d - Make sidebar resizable

Compare with previous version

added 4 commits

• 35aaf392 - Refactor toggle styles
• c11533bb - Do not use gin content form in ajax requests
• afc999c0 - Resolve #3456018 "Gin table scroll wrapper hides drop"
• 76b24c1d - Use fixed value sidebar on mobile

Compare with previous version

started a merge train

merged