feat(helm): add remaining options for bootstrap (#898)

### Description
This PR adds the possibility to pass any option for the bootstrap
component on the `opensearch-cluster` chart. As of now the only one that
can be set using the chart is `additionalConfig`.

### Issues Resolved

#667
. At least on the chart aspect.

### Check List
- [x] Commits are signed per the DCO using --signoff 
- [x] Unittest added for the new/changed functionality and all unit
tests are successful
- [ ] Customer-visible features documented
- [ ] No linter warnings (`make lint`)


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and
signing off your commits, please check
[here](https://github.com/opensearch-project/OpenSearch/blob/main/CONTRIBUTING.md#developer-certificate-of-origin).

---------

Signed-off-by: Igor Blackman <[email protected]>

charts/opensearch-cluster/templates/opensearch-cluster-cr.yaml

@@ -7,10 +7,7 @@ metadata:
 spec:
   {{- if .Values.opensearchCluster.bootstrap }}
   bootstrap:
-    {{- if .Values.opensearchCluster.bootstrap.additionalConfig }}
-    additionalConfig:
-      {{ toYaml .Values.opensearchCluster.bootstrap.additionalConfig | nindent 6 }}
-    {{- end }}
+    {{ toYaml .Values.opensearchCluster.bootstrap | nindent 4 }}
   {{- end }}
   {{- if .Values.opensearchCluster.initHelper }}
   initHelper: