Add KubeStash backup for oracle & solr editor options

[ArnobKumarSaha]

Follow-up to #1113 (neo4j & qdrant), covering Oracle and Solr.

Oracle

• charts/kubedbcom-oracle-editor-options/templates/kubestash/backupconfiguration.yaml (new) — target kind: Oracle, addon oracle-addon, task logical-backup. The options UI already had the "Enable Backup?" switch and the setBackup / onBackupSwitch handlers, and spec.admin.backup.enable was already true/true.

Solr
The BackupConfiguration template was already committed but could never render, because spec.admin.backup.enable was false/false and the UI had no way to turn backup on.

• values.yaml — spec.admin.backup.enable → default: true, toggle: true (README regenerated to match)
• ui/functions.js — added onBackupSwitch and setBackup, and exported both
• ui/create-ui.yaml — added the "Enable Backup?" switch

Heads-up on the addons

kubedb-kubestash-catalog currently has no oracle-addon and no solr-addon (it ships addons for cassandra, clickhouse, druid, elasticsearch, mariadb, mongodb, mssqlserver, mysql, neo4j, opensearch, postgres, qdrant, redis, singlestore, zookeeper). kubedb.dev/docs likewise has no backup/ guide for either. Until those addons land, a rendered BackupConfiguration for Oracle or Solr will reference a non-existent Addon and KubeStash will not resolve it. Merging this ahead of the catalog work is intentional; it should not reach users before the addons exist.

Verified

helm template on both charts: nothing renders with default values; with spec.backup.tool=KubeStash plus storageRef / retentionPolicy / encryptionSecret / schedule, a valid BackupConfiguration renders. Solr now renders from spec.backup.tool=KubeStash alone, confirming the toggle flip. ui/create-ui.yaml parses as YAML and ui/functions.js passes node --check.

[ArnobKumarSaha]

Need august KubeDB release