Closes gh-26782

Allow groups to be used with standard locations so that order of
profile-specific files is consistent.

Prior to this commit, the default search locations considered for
application properties/yaml files was the following:

	optional:classpath:/
	optional:classpath:/config/
	optional:file:./
	optional:file:./config/
	optional:file:./config/*/

Each of these locations was independent which could cause confusion
if certain combinations were used. For example, if profile-specific
files were added to `classpath:/` and `classpath:/config/` then the
latter would always override the former regardless of the profile
ordering.

This commit updates `StandardConfigDataLocationResolver` so that a
group of locations can be specified for each item. This allows us to
define the following set of search locations which provide more logical
ordering for profile-specific files

	optional:classpath:/;optional:classpath:/config/
	optional:file:./;optional:file:./config/;optional:file:./config/*/

Closes gh-26593

Closes gh-26781

Closes gh-26780

Closes gh-26779

Closes gh-26778

Closes gh-26777

Closes gh-26776

See gh-26765

See gh-26764

See gh-26761

See gh-26772

See gh-26771

See gh-26770

See gh-26763

See gh-26762

See gh-26760

* pr/26751:
  Polish "Fix typo in 'Reacting to the Maven plugin' title"
  Fix typo in 'Reacting to the Maven plugin' title

Closes gh-26751

See gh-26751

See gh-26751

Closes gh-26755

Update the `ConfigDataEnvironment` so that the `resolveProfileSpecific`
method of `ConfigDataLocationResolver` is no longer called when
resolving imports declared in a profile-specific file.

Fixes gh-26753

Closes gh-26754

Update `StandardConfigDataLocationResolver` so that profile-specific
imports can only be used when there is no parent import.

Prior to this commit, given the following application.properties file:

	spring.profiles.active=p1,p2
	spring.config.import=other.properties

We would attempt to import `other.properties`, `other-p1.properties`
and `other-p2.properties`. This seems quite confusing and when we really
only need to support profile-specific properties for the initial root
set of locations.

Fixes gh-26752

Closes gh-26748

Closes gh-26747

* pr/26737:
  Remove reference to surefirebooter JAR

Closes gh-26737

See gh-26737

Closes gh-26744

Closes gh-26743

Update `JarFile` and `JarFileWrapper` classes so that they no longer
close the `JarFile` early if a `SecurityManager` is in use.

Prior to this commit, the closed `JarFile` would cause (an ultimately
swallowed) NPE in `ZipFile` which manifested itself as a
`ClassNotFoundException` when starting the app.

Closes gh-25538

Closes gh-26741