Docs: Use task_id in examples of tasks (#30436)

We had been using `task_id:1` or `taskId:1` because it is parses as a
valid task identifier but the `:1` part is confusing. This replaces
those examples with `task_id` which matches the response from the list
tasks API.

Closes #28314

docs/reference/cluster/tasks.asciidoc

@@ -64,9 +64,10 @@ It is also possible to retrieve information for a particular task:
 
 [source,js]
 --------------------------------------------------
-GET _tasks/task_id:1 <1>
+GET _tasks/task_id <1>
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 // TEST[catch:missing]
 
 <1> This will return a 404 if the task isn't found.
@@ -75,9 +76,10 @@ Or to retrieve all children of a particular task:
 
 [source,js]
 --------------------------------------------------
-GET _tasks?parent_task_id=parentTaskId:1 <1>
+GET _tasks?parent_task_id=parent_task_id <1>
 --------------------------------------------------
 // CONSOLE
+// TEST[s/=parent_task_id/=node_id:1/]
 
 <1> This won't return a 404 if the parent isn't found.
 

docs/reference/docs/delete-by-query.asciidoc

@@ -357,9 +357,10 @@ With the task id you can look up the task directly:
 
 [source,js]
 --------------------------------------------------
-GET /_tasks/taskId:1
+GET /_tasks/task_id
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 // TEST[catch:missing]
 
 The advantage of this API is that it integrates with `wait_for_completion=false`
@@ -378,8 +379,9 @@ Any Delete By Query can be canceled using the <<tasks,Task Cancel API>>:
 
 [source,js]
 --------------------------------------------------
-POST _tasks/task_id:1/_cancel
+POST _tasks/task_id/_cancel
 --------------------------------------------------
+// TEST[s/task_id/node_id:1/]
 // CONSOLE
 
 The `task_id` can be found using the tasks API above.
@@ -397,8 +399,9 @@ using the `_rethrottle` API:
 
 [source,js]
 --------------------------------------------------
-POST _delete_by_query/task_id:1/_rethrottle?requests_per_second=-1
+POST _delete_by_query/task_id/_rethrottle?requests_per_second=-1
 --------------------------------------------------
+// TEST[s/task_id/node_id:1/]
 // CONSOLE
 
 The `task_id` can be found using the tasks API above.

docs/reference/docs/reindex.asciidoc

@@ -740,9 +740,10 @@ With the task id you can look up the task directly:
 
 [source,js]
 --------------------------------------------------
-GET /_tasks/taskId:1
+GET /_tasks/task_id
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 // TEST[catch:missing]
 
 The advantage of this API is that it integrates with `wait_for_completion=false`
@@ -761,9 +762,10 @@ Any Reindex can be canceled using the <<tasks,Task Cancel API>>:
 
 [source,js]
 --------------------------------------------------
-POST _tasks/task_id:1/_cancel
+POST _tasks/task_id/_cancel
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 
 The `task_id` can be found using the Tasks API.
 
@@ -780,9 +782,10 @@ the `_rethrottle` API:
 
 [source,js]
 --------------------------------------------------
-POST _reindex/task_id:1/_rethrottle?requests_per_second=-1
+POST _reindex/task_id/_rethrottle?requests_per_second=-1
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 
 The `task_id` can be found using the Tasks API above.
 

docs/reference/docs/update-by-query.asciidoc

@@ -415,9 +415,10 @@ With the task id you can look up the task directly:
 
 [source,js]
 --------------------------------------------------
-GET /_tasks/taskId:1
+GET /_tasks/task_id
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 // TEST[catch:missing]
 
 The advantage of this API is that it integrates with `wait_for_completion=false`
@@ -436,9 +437,10 @@ Any Update By Query can be canceled using the <<tasks,Task Cancel API>>:
 
 [source,js]
 --------------------------------------------------
-POST _tasks/task_id:1/_cancel
+POST _tasks/task_id/_cancel
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 
 The `task_id` can be found using the tasks API above.
 
@@ -455,9 +457,10 @@ using the `_rethrottle` API:
 
 [source,js]
 --------------------------------------------------
-POST _update_by_query/task_id:1/_rethrottle?requests_per_second=-1
+POST _update_by_query/task_id/_rethrottle?requests_per_second=-1
 --------------------------------------------------
 // CONSOLE
+// TEST[s/task_id/node_id:1/]
 
 The `task_id` can be found using the tasks API above.