[Stable plugin api] Drop api suffix in package names (#92905)

Refactoring that drops the api suffix from package name
This will have to be followed up by a plugins/examples fix in imports
Also set an artifact group name to `org.elasticsearch.plugin` in the plugin-api and plugin-analysis-api

libs/plugin-api/src/main/java/module-info.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-module org.elasticsearch.plugin.api {
-    exports org.elasticsearch.plugin.api;
-    exports org.elasticsearch.plugin.api.settings;
+module org.elasticsearch.plugin {
+    exports org.elasticsearch.plugin;
+    exports org.elasticsearch.plugin.settings;
 }

libs/plugin-api/src/main/java/org/elasticsearch/plugin/Extensible.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api;
+package org.elasticsearch.plugin;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/Inject.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api;
+package org.elasticsearch.plugin;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/Nameable.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api;
+package org.elasticsearch.plugin;
 
 /**
  * A named plugin component. Components with a name can be registered and fetched under a name given in

libs/plugin-api/src/main/java/org/elasticsearch/plugin/NamedComponent.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api;
+package org.elasticsearch.plugin;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/package-info.java

@@ -12,14 +12,12 @@
  * <ul>
  *      <li> The root package is org.elasticsearch.plugin</li>
  *      <li> Specialised API jars have their name following the root package.
+ *           Interfaces and annotations used by plugin developers should be placed under it.
  *           i.e. org.elasticsearch.plugin.analysis
  *      </li>
- *      <li> Interfaces and annotations used by plugin developers are in `api` package
- *           i.e org.elasticsearch.plugin.analysis.api or org.elasticsearch.plugin.api
-*       </li>
- *      <li> packages which are not meant to be used by plugin developers should not be subpackages of api
+ *      <li> packages which are not meant to be used by plugin developers should be under internal package suffix
  *           i.e org.elasticsearch.plugin.analysis.internal
  *      </li>
  * </ul>
  */
-package org.elasticsearch.plugin.api;
+package org.elasticsearch.plugin;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/AnalysisSettings.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/BooleanSetting.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/IntSetting.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/ListSetting.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/LongSetting.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;

libs/plugin-api/src/main/java/org/elasticsearch/plugin/settings/StringSetting.java

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.plugin.api.settings;
+package org.elasticsearch.plugin.settings;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;