Document executionPlanCacheKeyHash and executableQueryCacheHit (#2064)

Hi @henriknyman, it seems that those two log entries were missing in the
docs. Could you please take a look to see if I have documented them
correctly? Also, in which version have they been introduced? Thanks a
lot!

---------

Co-authored-by: Henrik Nyman <[email protected]>

Author: renetapopova

modules/ROOT/pages/monitoring/logging.adoc

@@ -1222,6 +1222,7 @@ If the type of the log entry is `query`, these additional fields are available:
 
 | id
 | The query ID.
+The ID is incremental, starting from 1 and resetting upon every Neo4j restart.
 Included when xref:configuration/configuration-settings.adoc#config_db.logs.query.enabled[`db.logs.query.enabled`] is `VERBOSE`.
 
 | elapsedTimeMs
@@ -1286,6 +1287,16 @@ See <<gql-error-information, GQL error information>> for details on the contents
 | The query plan.
 Included when xref:configuration/configuration-settings.adoc#config_db.logs.query.plan_description_enabled[`db.logs.query.plan_description_enabled`] is `true`.
 
+| executionPlanCacheKeyHash
+| The 32-bit hash of the cache key used to cache the execution plan.
+It is a fixed-length 8-character string of a hex-encoded integer value.
+Enabled by default only in the JSON format.
+If multiple query executions use the same cached execution plan, their hashes should match.
+For `event=start`, the value is `00000000`.
+
+| executableQueryCacheHit
+| Whether the query string matched a cached execution plan.
+
 |===
 
 If the type of the log entry is `transaction`, the following additional fields are available:
@@ -1311,6 +1322,7 @@ Either same as `authenticatedUser` or an impersonated user.
 
 | transactionId
 | ID of the transaction.
+
 |===
 
 [[gql-error-information]]