Fix ecs.Service resource's external name configuration and update loop issue

[sergenyalcin]

Description of your changes

This PR fixes the ecs.Service resource's external name configuration and resolves an update loop issue caused by incorrect task definition reference handling.

Problem

The ECS Service resource had two critical issues:

1. Incorrect external name ID construction: The external name configuration in config.go used an old implementation that concatenated parameters.cluster + parameters.name for ID construction. This didn't match the actual AWS resource ID format (the full ARN).
2. Task definition update loop: When task definitions were referenced and their revision changed (e.g., from family:1 to family:2), the controller would incorrectly detect a diff and trigger unnecessary updates because it was comparing the full ARN against just the family name.

Changes

External Name Configuration

• The external name configuration for this resource was previously done in the config.go file using custom GetExternalNameFn and GetIDFn functions
• This was an old implementation created before TemplatedStringAsIdentifier existed, essentially mimicking what that function does
• Replaced the old implementation with TemplatedStringAsIdentifier using the proper ARN template: arn:aws:ecs:<region>:<account_id>:service/{{ .parameters.cluster }}/{{ .external_name }}
• Everything remains the same except the ID calculation function (GetIDFn):
  • Before: Concatenation of parameters.cluster + parameters.name fields
  • Now: Correct ID format (full ARN of the resource)

Task Definition Reference

• Changed task definition reference extractor from reference.ExternalName() to common.ARNExtractor() in both ForProvider and InitProvider for v1beta1, v1beta2, and namespaced APIs
• Added custom diff handler to ignore task definition changes that only affect revision numbers (e.g., family:35 vs arn:aws:ecs:region:account:task-definition/family:35)

I have:

• Read and followed Crossplane's contribution process.
• Run make generate and committed the results (ideally in a separate commit).
• Not made any manual changes to generated files, and verified this with make check-diff.

How has this code been tested

Tested locally via uptest.
https://github.com/crossplane-contrib/provider-upjet-aws/actions/runs/21032450859

[sergenyalcin]

/test-examples="examples/ecs/cluster/v1beta1/service.yaml"