FCT-1232: Remove workspaces button, feature flag, gradient background (…

…#3623)

* refactor(mc-scripts): manually group some vendor chunks

* Revert "refactor(mc-scripts): manually group some vendor chunks"

This reverts commit 012ef1f.

* chore(app-kit): remove workspaces button and gradient background

.changeset/nervous-kangaroos-rush.md

@@ -0,0 +1,7 @@
+---
+'@commercetools-frontend/application-components': minor
+'@commercetools-frontend/application-shell': minor
+'@commercetools-frontend/constants': minor
+---
+
+Removes the workspaces button from app-bar, and the workspaces gradient background from public page layout.