Update `DataSourceHealthContributorAutoConfiguration` so that any
`AbstractRoutingDataSource` beans are still included in the overall
health. Prior to this commit, a regression in Spring Boot 2.2 meant
that if a single routing bean was found an `IllegalArgumentException`
would be thrown.

In Spring Boot 2.1 all `AbstractRoutingDataSource` would be filtered
from the results, but if no results existed the following was returned:

  "details": {
    "db": {
      "status": "UNKNOWN"
    },

In Spring Boot 2.2 we now always include routing datasource beans, even
if other non-routing database beans are found. The health details
includes `"routing" : true` to help users disambiguate any results.

Fixes gh-18661

Update `NamedContributorsMapAdapter` to check for `null` keys or values
during construction. Also update `HealthEndpointSupport` to allow
null component entries.

See gh-18687

Update `HealthEndpointSupport` so that aggregate elements that don't
ultimately provide a contribution are filtered out. Prior to this
commit an NPE was returned when calculating the aggregate status.

Fixes gh-18687

* pr/18702:
  Make optimizedLaunch property name more consistent

Closes gh-18702

See gh-18702

Closes gh-18713

* pr/18705:
  Fix typos

Closes gh-18705

See gh-18705

* pr/18697:
  Polish

Closes gh-18697

See gh-18697

* pr/18689:
  Fix Mockito deprecations

Closes gh-18689

See gh-18689

Closes gh-18695

* pr/18566:
  Rename `max-http-post-size` server property

Closes gh-18566

Rename `max-http-post-size` to `max-http-form-post-size` for Jetty and
Tomcat to make it clearer that they only apply to POSTed form content.

See gh-18566

Closes gh-18694

Closes gh-18693

* pr/18536:
  Polish "Upgrade to Jetty 9.4.21.v20190926"
  Upgrade to Jetty 9.4.21.v20190926

Closes gh-18536

See gh-18536

See gh-18536

Closes gh-18691

Closes gh-18660

Closes gh-18679

* pr/18673:
  Polish "Apply dependsOn semantic between Liquibase and JPA"
  Apply dependsOn semantic between Liquibase and JPA

Closes gh-18673

See gh-18673

This commits restores the dependency between Liquibase and the JPA
EntityManager even if a custom `SpringLiquibase` is configured.

See gh-18673

This commit removes the override proxyBeanMethods as the aliased
attribute is taking precedence.

Closes gh-18682

* pr/18604:
  Optimize debug level logs

Closes gh-18604

See gh-18604

* pr/18632:
  Polish "Add missing package-info files"
  Add missing package-info files

Closes gh-18632

See gh-18632

See gh-18632

* pr/18637:
  Narrow type for Tomcat 'locale' and 'encoding' properties

Closes gh-18637

See gh-18637

* pr/18675:
  Polish "Restore proxying of @Bean methods in @TestConfiguration"
  Restore proxying of @Bean methods in @TestConfiguration

Closes gh-18675

See gh-18675

See gh-18675