fix(eks): Add reconciliation for addon configurationValues

[smcavallo]

Description of your changes

eks addon configurationValues is supported already in the spec but is not included in isUpToDate and therefore can never be changed with the provider.
https://github.com/crossplane-contrib/provider-aws/blob/master/apis/eks/v1alpha1/zz_addon.go#L40-L43

This PR adds the custom isUpToDate in order to update the configurationValues
The configurationValues is a string value but both json and yaml are supported. (See - https://aws.amazon.com/blogs/containers/amazon-eks-add-ons-advanced-configuration/)
Note the implementation for the string comparison.
Whitespace and indendation is difficult to get correct when using a string value.
This PR does UnMarshal and Marshal the json or yaml to ensure that the comparison is more accurate. It lessens the risk that this provider will continually request an update of the external resource due to formatting, similar to the "normalization" done with iam policies. Unit test cases have been added for testing format differences.

The addOn example has been updated to reflect yaml definition but json is supported as well.

yaml:

    configurationValues: |
      controller:
        podAnnotations:
          fluentbit.io/exclude: "true"

json:

      configurationValues: '{"controller": {"podAnnotations": {"fluentbit.io/exclude":
      "true"}}}'

What this PR does NOT do:

• Any validation for yaml/json formatting
• Each addOn publishes a configuration schema. This provider does not validate the cr against the provided schema. This PR will send the update and aws will reject the change due to invalid schema

Fixes #

I have:

• [X ] Read and followed Crossplane's contribution process.
• [X ] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

• define configurationValues for an addOn using the above json

• ensure provider-aws reconciles the resource and json configurationValues appear in the console

• ensure that upon the next reconcile the External resource is up to date

• set configurationValues to ""

• ensure provider-aws reconciles the resource and the default value of - appears in the console

• ensure that upon the next reconcile the External resource is up to date

• do the same as the above but with yaml

• ensure that no changes are made when configurationValues is not defined for an addOn - provider-aws reconciles the resource and the default value of - appears in the console

• ensure that the isUpToDate for configurationValues handles exceptions and returns them so they can be written as errors in the logs

• ensure that when using values which violate the schema the provider throws the exception to the logs:

2023-08-18T03:16:27.324Z        DEBUG   events  cannot update Addon in AWS: InvalidParameterException: ConfigurationValue provided in request is not supported: Yaml schema validation failed with error: [$.controller2: is not defined in the schema and the schema does not allow additional properties]
{
  RespMetadata: {
    StatusCode: 400,
    RequestID: ""
  },

[MisterMX]

LGTM. Thank you very much for your contribution @smcavallo!