Edit starters dialog needs some 'revamping'

Problems:

• The 'edit starters' dialog doesn't show spring-cloud starters.
• The dialog has a long list of disorganized starters and no search box

Possible solutions:

• Find a way to discover cloud starters, similar to how we discover the 'core boot'' starters.
• There may be other starters which are not discoverable now because they use a separate 'bom'. For example, vaadin.
• Can we categorize the starters? (This might be tricky, unless we can somehow harness the categories from start.spring.io)
• Add a search box, to the dialog