[refactoring] Migrate Boot 2 auto-config to Boot

[BoykoAlex]

Boot 2: Configuration beans to scan are listed in spring.factories file under key org.springframework.boot.autoconfigure.EnableAutoConfiguration as classes FQNs separated by commas

Boot 3: spring.factories key org.springframework.boot.autoconfigure.EnableAutoConfiguration is retired. Classes FQNs go into a separate file org.springframework.boot.autoconfigure.AutoConfiguration.imports with each FQN on a new line

This to be implemented in rewrite-spring as a recipe and to be included in the Boot 3 migration aggregate recipe

[BoykoAlex]

Looks like Tyler is going to take on this issue in rewrite-spring: openrewrite/rewrite-spring#197

[BoykoAlex]

The recipe is part of the Boot 3 upgrade in the latest snapshot. Also pushed this: da35dca. Tried the the upgrade to boot 3 with spring.factories with auto-config key. Worked. Extracted the entry into a separate imports file