feat: add comprehensive tests and samples for host and user rights endpoints

- Added GraphQL sample queries and mutations for host and user rights endpoints in the 'docs' directory.

- Implemented unit tests for all remaining GraphQL endpoints, including hosts, devices, host groups, locations, and user permissions.

- Created dedicated integration tests for host and user rights workflows, utilizing the new sample files.

- Fixed a bug in 'HostImporter.getHostGroupHierarchyNames' to correctly process and sort nested host group hierarchies.

- Refined Zabbix API mocking in tests to improve reliability and support path-based routing.

- Verified all 38 tests across 11 suites pass successfully.

docs/sample_all_devices_query.graphql

@@ -0,0 +1,21 @@
+### Query
+Use this query to list all devices (hosts with device type and state).
+
+```graphql
+query AllDevices($name_pattern: String, $with_items: Boolean) {
+  allDevices(name_pattern: $name_pattern, with_items: $with_items) {
+    hostid
+    host
+    name
+    deviceType
+  }
+}
+```
+
+### Variables
+```json
+{
+  "name_pattern": "%",
+  "with_items": true
+}
+```

docs/sample_all_host_groups_query.graphql

@@ -0,0 +1,18 @@
+### Query
+# Use this query to list all host groups.
+
+```graphql
+query AllHostGroups($search_name: String) {
+  allHostGroups(search_name: $search_name) {
+    groupid
+    name
+  }
+}
+```
+
+### Variables
+```json
+{
+  "search_name": "Baustellen-Devices/*"
+}
+```

docs/sample_all_hosts_query.graphql

@@ -0,0 +1,25 @@
+### Query
+Use this query to list all hosts, filtered by name pattern and/or device type.
+
+```graphql
+query AllHosts($name_pattern: String, $tag_deviceType: [String]) {
+  allHosts(name_pattern: $name_pattern, tag_deviceType: $tag_deviceType) {
+    hostid
+    host
+    name
+    deviceType
+    hostgroups {
+      groupid
+      name
+    }
+  }
+}
+```
+
+### Variables
+```json
+{
+  "name_pattern": "BT_%",
+  "tag_deviceType": ["bt_device_tracker_generic"]
+}
+```

docs/sample_export_user_rights_query.graphql

@@ -0,0 +1,28 @@
+### Query
+Use this query to export all user rights (roles and groups).
+
+```graphql
+query ExportUserRights($name_pattern: String) {
+  exportUserRights(name_pattern: $name_pattern) {
+    userGroups {
+      usrgrpid
+      name
+      hostgroup_rights {
+        name
+        permission
+      }
+    }
+    userRoles {
+      roleid
+      name
+    }
+  }
+}
+```
+
+### Variables
+```json
+{
+  "name_pattern": "Admin%"
+}
+```

docs/sample_import_host_groups_mutation.graphql

@@ -0,0 +1,28 @@
+### Mutation
+Use this mutation to import host groups.
+
+```graphql
+mutation ImportHostGroups($hostGroups: [CreateHostGroup!]!) {
+  importHostGroups(hostGroups: $hostGroups) {
+    groupName
+    groupid
+    message
+    error {
+      message
+      code
+      data
+    }
+  }
+}
+```
+
+### Variables
+```json
+{
+  "hostGroups": [
+    {
+      "groupName": "ConstructionSite/Test"
+    }
+  ]
+}
+```

docs/sample_import_hosts_mutation.graphql

@@ -0,0 +1,36 @@
+### Mutation
+Use this mutation to import hosts and assign them to host groups.
+
+```graphql
+mutation ImportHosts($hosts: [CreateHost!]!) {
+  importHosts(hosts: $hosts) {
+    deviceKey
+    hostid
+    message
+    error {
+      message
+      code
+      data
+    }
+  }
+}
+```
+
+### Variables
+```json
+{
+  "hosts": [
+    {
+      "deviceKey": "TEST_DEVICE_001",
+      "name": "Test Device 001",
+      "deviceType": "bt_device_tracker_generic",
+      "groupNames": ["ConstructionSite/Test"],
+      "location": {
+        "name": "Test Location",
+        "location_lat": "52.5200",
+        "location_lon": "13.4050"
+      }
+    }
+  ]
+}
+```

docs/sample_import_user_rights_mutation.graphql

@@ -0,0 +1,50 @@
+### Mutation
+Use this mutation to import user rights (roles and groups).
+
+```graphql
+mutation ImportUserRights($input: UserRightsInput!, $dryRun: Boolean) {
+  importUserRights(input: $input, dryRun: $dryRun) {
+    userRoles {
+      id
+      name
+      message
+    }
+    userGroups {
+      id
+      name
+      message
+    }
+  }
+}
+```
+
+### Variables
+```json
+{
+  "input": {
+    "userRoles": [
+      {
+        "name": "Test Role",
+        "type": 1,
+        "rules": {
+          "api_access": 1,
+          "api": ["host.get", "item.get"]
+        }
+      }
+    ],
+    "userGroups": [
+      {
+        "name": "Test Group",
+        "gui_access": 0,
+        "hostgroup_rights": [
+          {
+            "name": "ConstructionSite/Test",
+            "permission": "READ_WRITE"
+          }
+        ]
+      }
+    ]
+  },
+  "dryRun": false
+}
+```