Update spring-boot-loader to allow `-javaagent` instrumentation when
running from executable jars.

Prior to this commit the `Launcher` skipped the application classloader
and instead used the system classloader as a parent. This was to ensure
that locally packaged classes were always loaded by the classloader
that had access to nested jars.  Unfortunately when using the
`-javaagent` option, it is the application classloader that is modified.

The `Launcher` class now uses the application classloader as parent
and `LaunchedURLClassLoader` has been updated to always search local
URLs before delegating to the parent. This is very similar to the way
that most application servers handle the loading of war files.

Issue: #56232870

Snake is stateful so it should be one per connection. Echo is the
opposite.

Update CLI SpringMvcCompilerAutoConfiguration to recognize Spring's new
@RestController annotation.

Add version properties to dependencies POM so that users can easily
override. Also use consistent naming for all property keys.

Move JPA @Condition annotations from JpaBaseConfiguration to
HibernateJpaAutoConfiguration since they are not inherited.

Provide accurate InputStream.available() results by using the size
attribute of the ZipEntry. This helps improve performance with
CGLib and also fixes issues where libraries expect that a non-zero
result from available() indicates that read() will not return -1.

Add maven-compler-plugin to starter POM in an attempt to fix drone.io
errors downstream.

Update RunMojo to include an @Execute annotation. Allows the use of
`mvn spring-boot:run` without having to compile/package first. Now a
command like `mvn clean spring-boot:run` works.

The phase for @Execute annotation is along the lines of what is used
for the `jetty:run` plugin.

Update SpringIntegrationCompilerAutoConfiguration to use the managed
version of spring-integration-groovy-dsl.

Fix classloader issues by excluding spring JARs from test classpath
and also include spring-integration-groovy-dsl as a managed dependency.

Cleaned up file separators to prevent tests failing on Windows.

Update Launcher to correctly handle spaced in file paths.

Refactor JavaLoggerSystemTests to make use of OutputCapture and ensure
that captured output never includes ANSI symbols.

The spring property should have been spring.profiles.active instead of
spring.active.profiles.

Fix TomcatEmbeddedServletContainerFactory to set a MERGED_WEB_XML
attribute when JSPs are used. This is required for EL support with
JSPs since Jasper checks the version number in the web.xml. Without
any web.xml Jasper default to disabling EL.

Issue: #55752948

Use standard class loading delegation with Tomcat.

Include resource mapping for web-jar resources.

Issue: #55752928

Change ConfigFileApplicationContextInitializer to add config file
property sources after existing sources. This allows environment
variables and system properties to override file properties.

Issue: #55739594