Adds support for host tags (#2140)

## Sumary
When dealing with multiple hosts, it can be hard for customers filter
through and figure out which host to query metric data from. This PR
aims to make this easier by adding support for host tags so that there
is another layer of filtering / grouping applied for hosts.

## Detailed explanation
- Adds new UI components to allow adding one or more host tag filter,
and a switch to choose between `AND/OR` and `OR` operators when using
more than one filter following Zabbix's UI:
  

https://github.com/user-attachments/assets/c971f5eb-7e93-4238-bd6b-902cc657c014


https://github.com/user-attachments/assets/5f8996de-684e-4ffa-b98e-8e205c4fc1df

- Modifies the existing `getHosts` function to make a call to the
backend with a few additional parameters to `extend` (essentially
extract) the host tags for a given selected group. No backend changes
were required for this.

## Why
To make it easier for customers to query metric data when dealing with
multiple hosts.

## How to test
- Go to explore or a dashboard and create a Zabbix query where the query
type is `Metrics`
- The easiest way to test is by selecting `/.*/` for Groups, checking
the returned `Hosts` they should all be there
- Add a host tag filter and change the keys and operators as well as
switching from `AND/OR` to `OR` you should see how the values returned
for `Host` changes

## Future work
Adding variable support for host tags once this is completed.

Fixes:
https://github.com/orgs/grafana/projects/457/views/40?pane=issue&itemId=3609900134&issue=grafana%7Coss-big-tent-squad%7C126
and https://github.com/grafana/grafana-zabbix/issues/927

---------

Co-authored-by: ismail simsek <ismailsimsek09@gmail.com>

pkg/zabbix/models.go

@@ -51,7 +51,7 @@ type Item struct {
 	Delay      string     `json:"delay,omitempty"`
 	Units      string     `json:"units,omitempty"`
 	ValueMapID string     `json:"valuemapid,omitempty"`
-	Tags       []ItemTag  `json:"tags,omitempty"`
+	Tags       []Tag  	  `json:"tags,omitempty"`
 }
 
 type ItemHost struct {
@@ -59,7 +59,7 @@ type ItemHost struct {
 	Name string `json:"name,omitempty"`
 }
 
-type ItemTag struct {
+type Tag struct {
 	Tag   string `json:"tag,omitempty"`
 	Value string `json:"value,omitempty"`
 }
@@ -90,9 +90,10 @@ type Group struct {
 }
 
 type Host struct {
-	Name string `json:"name"`
-	Host string `json:"host"`
-	ID   string `json:"hostid"`
+	Name string    `json:"name"`
+	Host string    `json:"host"`
+	ID   string    `json:"hostid"`
+	Tags []Tag 	   `json:"tags,omitempty"`
 }
 
 type Application struct {