Variables: Allow fetching disabled items for Item type variable (#2109)

This PR adds support for showing disabled items when using the `Item`
type template variable. Similar to how we support disabled items today
in our query editor:


<img width="435" height="254" alt="Screenshot 2025-10-21 at 9 00 11 AM"
src="https://github.com/user-attachments/assets/832537c8-84c3-45fe-a85d-b16c8e15f759"
/>

In this example, the host contains a disabled item `CPU iowait time`

<img width="1763" height="46" alt="Screenshot 2025-10-21 at 9 02 08 AM"
src="https://github.com/user-attachments/assets/85419e88-280d-4dce-baee-bf403e1de05d"
/>

Which we can now show and hide from the variable in Grafana:



https://github.com/user-attachments/assets/eca9327e-40a6-4852-92e9-71ff1ad9ea32

I also removed some deprecated types and packages :)!
Fixes: #2025

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/datasource/datasource.ts

@@ -11,7 +11,7 @@ import responseHandler from './responseHandler';
 import problemsHandler from './problemsHandler';
 import { Zabbix } from './zabbix/zabbix';
 import { ZabbixAPIError } from './zabbix/connectors/zabbix_api/zabbixAPIConnector';
-import { ProblemDTO, VariableQueryTypes } from './types';
+import { LegacyVariableQuery, ProblemDTO, VariableQuery, VariableQueryTypes } from './types';
 import { ZabbixMetricsQuery, ShowProblemTypes } from './types/query';
 import { ZabbixDSOptions } from './types/config';
 import {
@@ -36,6 +36,7 @@ import {
 } from '@grafana/data';
 import { AnnotationQueryEditor } from './components/AnnotationQueryEditor';
 import { trackRequest } from './tracking';
+import { lastValueFrom } from 'rxjs';
 
 export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDSOptions> {
   name: string;
@@ -212,14 +213,14 @@ export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDS
 
     let rsp: any;
     try {
-      rsp = await getBackendSrv()
-        .fetch({
+      rsp = await lastValueFrom(
+        getBackendSrv().fetch({
           url: '/api/ds/query',
           method: 'POST',
           data: body,
           requestId,
         })
-        .toPromise();
+      );
     } catch (err) {
       return toDataQueryResponse(err);
     }
@@ -404,7 +405,7 @@ export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDS
       },
     };
 
-    const response: any = await getBackendSrv().fetch<any>(requestOptions).toPromise();
+    const response: any = await lastValueFrom(getBackendSrv().fetch<any>(requestOptions));
     return response.data;
   }
 
@@ -813,12 +814,12 @@ export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDS
   /**
    * Find metrics from templated request.
    *
-   * @param  {string} query Query from Templating
+   * @param  {LegacyVariableQuery} query Query from Templating
    * @param options
    * @return {string}       Metric name - group, host, app or item or list
    *                        of metrics in "{metric1, metric2,..., metricN}" format.
    */
-  metricFindQuery(query, options) {
+  metricFindQuery(query: LegacyVariableQuery, options) {
     let resultPromise;
     let queryModel = _.cloneDeep(query);
 
@@ -835,6 +836,7 @@ export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDS
       queryModel[prop] = this.replaceTemplateVars(queryModel[prop], {});
     }
 
+    queryModel = queryModel as VariableQuery;
     const { group, host, application, item } = queryModel;
 
     switch (queryModel.queryType) {
@@ -856,7 +858,8 @@ export class ZabbixDatasource extends DataSourceApi<ZabbixMetricsQuery, ZabbixDS
           queryModel.host,
           queryModel.application,
           queryModel.itemTag,
-          queryModel.item
+          queryModel.item,
+          { showDisabledItems: queryModel.showDisabledItems }
         );
         break;
       case VariableQueryTypes.ItemValues: