CloudWatch: prevent log groups from being removed on query change. (#47994)

* CloudWatch: prevent log groups from being removed on query change.

Previously when a query was changed the existing log groups for that query were "dropped". The fix is to combine the
new query with the existing query object in memory to preserve the log groups.

fixes #33626

* CloudWatch: fix typos in runWithRetry documentation

* chore: fix eslint issue

public/app/plugins/datasource/cloudwatch/components/LogsCheatSheet.tsx

@@ -229,8 +229,15 @@ export default class LogsCheatSheet extends PureComponent<
       <div
         className="cheat-sheet-item__example"
         key={expr}
-        onClick={(e) =>
-          this.onClickExample({ refId: 'A', expression: expr, queryMode: 'Logs', region: 'default', id: 'A' })
+        onClick={() =>
+          this.onClickExample({
+            refId: this.props.query.refId ?? 'A',
+            expression: expr,
+            queryMode: 'Logs',
+            region: this.props.query.region,
+            id: this.props.query.refId ?? 'A',
+            logGroupNames: 'logGroupNames' in this.props.query ? this.props.query.logGroupNames : [],
+          })
         }
       >
         <pre>{renderHighlightedMarkup(expr, keyPrefix)}</pre>