Rest HL client: Add put watch action (#32026)

Relates #29827

This implementation behaves like the current transport client, that you basically cannot configure a Watch POJO representation as an argument to the put watch API, but only a bytes reference. You can use the the `WatchSourceBuilder` from the `org.elasticsearch.plugin:x-pack-core` dependency to build watches.

This commit also changes the license type to trial, so that watcher is available in high level rest client tests.

/cc @hub-cap

docs/java-rest/high-level/supported-apis.asciidoc

@@ -57,7 +57,8 @@ The Java High Level REST Client supports the following Miscellaneous APIs:
 
 include::miscellaneous/main.asciidoc[]
 include::miscellaneous/ping.asciidoc[]
-include::miscellaneous/x-pack-info.asciidoc[]
+include::x-pack/x-pack-info.asciidoc[]
+include::x-pack/watcher/put-watch.asciidoc[]
 
 == Indices APIs
 

docs/java-rest/high-level/x-pack/watcher/put-watch.asciidoc

@@ -0,0 +1,55 @@
+[[java-rest-high-x-pack-watcher-put-watch]]
+=== X-Pack Info API
+
+[[java-rest-high-x-pack-watcher-put-watch-execution]]
+==== Execution
+
+General information about the installed {watcher} features can be retrieved
+using the `watcher()` method:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/WatcherDocumentationIT.java[x-pack-put-watch-execute]
+--------------------------------------------------
+<1> Allows to store the watch, but to not trigger it. Defaults to `true`
+
+[[java-rest-high-x-pack-watcher-put-watch-response]]
+==== Response
+
+The returned `XPackPutWatchResponse` contain `created`, `id`,
+and `version` information.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/WatcherDocumentationIT.java[x-pack-put-watch-response]
+--------------------------------------------------
+<1> `_id` contains id of the watch
+<2> `created` is a boolean indicating whether the watch was created for the first time
+<3> `_version` returns the newly created version
+
+[[java-rest-high-x-pack-watcher-put-watch-async]]
+==== Asynchronous Execution
+
+This request can be executed asynchronously:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/WatcherDocumentationIT.java[x-pack-put-watch-execute-async]
+--------------------------------------------------
+<1> The `XPackPutWatchRequest` to execute and the `ActionListener` to use when
+the execution completes
+
+The asynchronous method does not block and returns immediately. Once it is
+completed the `ActionListener` is called back using the `onResponse` method
+if the execution successfully completed or using the `onFailure` method if
+it failed.
+
+A typical listener for `XPackPutWatchResponse` looks like:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/WatcherDocumentationIT.java[x-pack-put-watch-execute-listener]
+--------------------------------------------------
+<1> Called when the execution is successfully completed. The response is
+provided as an argument
+<2> Called in case of failure. The raised exception is provided as an argument