This commit adds spring-boot-starter-micrometer-metrics and
spring-boot-starter-micrometer-metrics-test.
It also uses the new starters in smoke tests and in other starters,
which depended on spring-boot-micrometer-metrics.
Closes gh-48161
Polish test starter to:
- Align dependencies of starters and their -test companions
- Pull in regular starters from test starters
See gh-46356
Co-authored-by: Phillip Webb <phil.webb@broadcom.com>