Sanitize parameters when comparing with existing ecs_taskdefinition

[nikhilo]

SUMMARY

Addresses issues with idempotence for ecs_taskdefinition module

• If certain parameters are templatized, they will have different data types in the existing task definition as compared to the requested values.
  e.g. cpu: "{{ nginx.cpu }}" will appear as cpu: "1111" (string) in the module invocation. And when you invoke this the second time, the module fails to detect that the CPU value is actually the same. And registers a new task definition.
• Certain (non essential) parameters can be omitted from the module invocation. But on the second invocation when we compare the module parameters with existing task_definition(s), these parameters appear in the comparison and fail a potential match.
  e.g. Key essential in containers. Key protocol in containers[].portMapping

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

ecs_taskdefinition

ADDITIONAL INFORMATION

Unfortunately the module output does not indicate why it's registering a new task definition. Hence command output might not be very useful.

[ansibullbot]

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[alinabuzachis]

Hi @nikhilo, thank you for your contribution. May you kindly add a changelog fragment https://docs.ansible.com/ansible/latest/community/development_process.html#changelogs and a functional test? If you need any help, feel free to reach out on IRC #ansible-aws.

[markuman]

Hm, I don't know how, but some of the changed lines from this PR are already in the main branch.
Furthermore @alinabuzachis made a lot of in this direction with PR #574
I think we can close this for now.
Feel free to re-open this PR if necessary or contribute more features and bug fixes.