Feat: get pending config

[Tinyblargon]

Add ways to check if there are pending config changes.
Add a way to get the active config, as the normal config has the pending changes included.
Improved some tests due to the new mocks.

Closes #458

[Copilot]

Pull Request Overview

This PR adds functionality to check for pending configuration changes and retrieve the active configuration without pending changes. The PR introduces new methods to differentiate between the complete configuration (with pending changes) and the active configuration (without pending changes).

• Adds methods to check if there are pending configuration changes for VMs and LXC containers
• Provides new functions to get active configuration without pending changes
• Improves existing code to use the new pending changes detection

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
proxmox/vmref.go	Adds core methods for checking pending changes and getting pending config
proxmox/vmref_test.go	Tests for the new pending changes functionality
proxmox/config__qemu.go	Updates VM config handling to use new pending changes methods
proxmox/config__qemu_test.go	Tests for active QEMU configuration without pending changes
proxmox/config__lxc__new.go	Updates LXC config handling to use new pending changes methods
proxmox/config__lxc__new_test.go	Tests for active LXC configuration without pending changes
proxmox/config__guest.go	Updates guest config to use new pending changes methods
proxmox/client__new.go	Adds guest check functionality to new client interface
proxmox/client__new__mock.go	Mock implementations for new client methods
proxmox/client__api.go	Adds API method to get guest pending changes
proxmox/client__api__mock.go	Mock implementation for API pending changes method
proxmox/client__api__reusable.go	Updates API helper methods with better error handling

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[Copilot]

The comment incorrectly refers to 'LXC container' but this function is for QEMU VMs. It should say 'QEMU VM' instead.

Suggested change

	// NewRawConfigQemuFromApi returns the configuration of the LXC container.
	// NewRawConfigQemuFromApi returns the configuration of the QEMU VM.

[Copilot]

[nitpick] The comment is correct for LXC, but there's an inconsistency with the QEMU version which incorrectly mentions LXC. Consider standardizing the comment format.

Suggested change

	// NewRawConfigLXCFromAPI returns the configuration of the LXC container.
	// Including pending changes.
	// NewRawConfigLXCFromAPI returns the configuration of the LXC container, including pending changes.

[Copilot]

[nitpick] The comment is correct for LXC, but there's an inconsistency with the QEMU version which incorrectly mentions LXC. Consider standardizing the comment format.

Suggested change

	// NewActiveRawConfigLXCFromApi returns the active configuration of the LXC container.
	// Without pending changes.
	// NewActiveRawConfigLXCFromApi returns the active configuration of the LXC container, excluding pending changes.

[Copilot]

The comment incorrectly refers to 'LXC container' but this function is for QEMU VMs. It should say 'QEMU VM' instead.