Add indexing and search index settings (opensearch-project#667)

* Add indexing and search index settings

This commit adds indexing and search settings to index settings. These
settings allow configuring of slow logs for indexing and search, as
well as setting search idle after.

Search idle after duplicates the individual
IndexSettings::searchIdleAfter property, but this pattern is already
present e.g. IndexSettings::blocks and IndexSettings::blocksReadOnly,
IndexSettings::blocksRead, etc.

Signed-off-by: Russ Cam <russcam@canva.com>

* add changelog entry

Signed-off-by: Russ Cam <russcam@canva.com>

* Add documentation and sample

Signed-off-by: Russ Cam <russcam@canva.com>

* Update IndexTemplates

Signed-off-by: Russ Cam <russcam@canva.com>

---------

Signed-off-by: Russ Cam <russcam@canva.com>
Signed-off-by: Andriy Redko <andriy.redko@aiven.io>

gradle/wrapper/gradle-wrapper.properties

@@ -28,7 +28,7 @@
 
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionSha256Sum=591855b517fc635b9e04de1d05d5e76ada3f89f5fc76f87978d1b245b4f69225
+distributionSha256Sum=3e1af3ae886920c3ac87f7a91f816c0c7c436f276a6eefdb3da152100fef72ae

gradlew

@@ -145,15 +145,15 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -202,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \