reverted and changes Alert Channel changes as per latest API v4 changes

[srbhaakamai]

📝 Description

What does this PR do and why is this change necessary?

✔️ How to Test

What are the steps to reproduce the issue or verify the changes?

How do I run the relevant unit/integration tests?
srbha@blr-mpo40 linodego % export LINODE_TOKEN="" && export LINODE_API_VERSION="v4beta" && go test -count=1 ./test/integration -run "TestMonitorAlertDefinition" -v
=== RUN TestMonitorAlertDefinition_smoke
--- PASS: TestMonitorAlertDefinition_smoke (66.19s)
=== RUN TestMonitorAlertDefinitions_List
--- PASS: TestMonitorAlertDefinitions_List (1.37s)
=== RUN TestMonitorAlertDefinition_CreateWithIdempotency
--- PASS: TestMonitorAlertDefinition_CreateWithIdempotency (3.88s)
PASS
ok github.com/linode/linodego/test/integration 72.096s

📷 Preview

If applicable, include a screenshot or code snippet of this change. Otherwise, please remove this section.

[Copilot]

Pull request overview

Re-enables Monitor alert channel functionality and related integration tests, updating the Alert Channel model to match the latest API v4 shape.

Changes:

• Re-enabled integration tests that depend on listing alert channels and selecting a channel ID dynamically.
• Implemented AlertChannel types (including content/details blocks) and restored ListAlertChannels.
• Added JSON unmarshalling for created/updated timestamps using parseabletime.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 7 comments.

File	Description
test/integration/monitor_alert_definitions_test.go	Re-enables alert channel listing tests and uses live channel discovery for alert definition creation.
monitor_alert_channels.go	Restores alert channel API surface (types + ListAlertChannels) updated for API v4 response schema.

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[satkumar-akamai]

@srbhaakamai

1. For the List Channels API, the content and details fields currently contain essentially the same data but with different structure. We have kept both fields for backward compatibility, but content will be removed from the response in the future.
   Please ensure that the test suites do not heavily depend on the content field.

2. Please update the latest ENUM in Alert Status field in Alert Management APIs (provided in the api spec)

[satkumar-akamai]

Changes looks good as per API Spec.

[yec-akamai]

Overall looks good. Can you fix the comments please?

[yec-akamai]

Can you also run the integration test and re-generate the fixtures please?

[srbhaakamai]

@yec-akamai i fixed all comments from you and copilot. Please check. i marked most of them which were simple as resolved from my side. please have a look and request further review/approval.

Srinidhi

[yec-akamai]

Considering there are more statuses added, just checking if it's enabling status is probably not so useful.

I think we can change this function to intake and wait for a specific a target status. We can change the function head to be

func (client Client) WaitForAlertDefinitionStatus(
	ctx context.Context,
    status AlertDefinitionStatus,
	serviceType string,
	alertID int,
	timeoutSeconds int,
) {...}

and wait for the target status.