[receiver/vcenter] Adds Initial Support for VM Templates (#32831)

**Description:** <Describe what has changed.>
- The Cluster `vcenter.cluster.vm.count` metric now does not include
templates in the returned values.
- A new (default disabled with warning) Cluster
`vcenter.cluster.vm_template.count`metric is added to count only VM
templates.
- VM Template Resource Attributes `vcenter.vm_template.name` and
`vcenter.vm_template.id` have been added (default disabled with
warning). If disabled, resources will no longer be created for VM
templates.
- Trimmed down VM Template metrics to a single expected metric.
- Fixed integration test build tag that was accidentally removed in
previous PR

**Link to tracking Issue:** <Issue number if applicable>
#32821 

**Testing:** <Describe what testing was performed and which tests were
added.>
Unit/integration tests updated and tested. Local environment tested.

**Documentation:** <Describe the documentation added.>
New documentation generated based on the metadata.

.chloggen/fix_vcenter-vm-template-add.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: vcenterreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Adds initially disabled functionality for VM Templates"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [32821]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/vcenterreceiver/client.go

@@ -137,6 +137,7 @@ func (vc *vcenterClient) VMs(ctx context.Context) ([]mo.VirtualMachine, error) {
 	err = v.Retrieve(ctx, []string{"VirtualMachine"}, []string{
 		"config.hardware.numCPU",
 		"config.instanceUuid",
+		"config.template",
 		"runtime.powerState",
 		"runtime.maxCpuUsage",
 		"summary.quickStats.guestMemoryUsage",

receiver/vcenterreceiver/documentation.md

@@ -458,6 +458,14 @@ metrics:
     enabled: true
 ```
 
+### vcenter.cluster.vm_template.count
+
+The number of virtual machine templates in the cluster.
+
+| Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
+| ---- | ----------- | ---------- | ----------------------- | --------- |
+| {virtual_machine_templates} | Sum | Int | Cumulative | false |
+
 ### vcenter.vm.memory.utilization
 
 The memory utilization of the VM.
@@ -480,3 +488,5 @@ The memory utilization of the VM.
 | vcenter.virtual_app.name | The name of the vApp. | Any Str | false |
 | vcenter.vm.id | The instance UUID of the virtual machine. | Any Str | true |
 | vcenter.vm.name | The name of the virtual machine. | Any Str | true |
+| vcenter.vm_template.id | The instance UUID of the virtual machine template. | Any Str | false |
+| vcenter.vm_template.name | The name of the virtual machine template. | Any Str | false |

receiver/vcenterreceiver/integration_test.go

@@ -1,6 +1,8 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+//go:build integration
+
 package vcenterreceiver // import github.com/open-telemetry/opentelemetry-collector-contrib/receiver/vcenterreceiver
 
 import (