backstage release v0.56.0

In this release:

• filtering logic was added to the Deployments and Clusters pages;
• “Deployment Type” filter was added to the Deployments page;
• “Type” filter was added to the Clusters page;
• “MultipleSelect” component styles were improved to provide a more compact view;
• a counter for table items was added to the table titles. See ./docs/releases/v0.56.0-changelog.md for more information.