feat: [CI-14214] : Added PLUGIN_USER_ROLE_EXTERNAL_ID to pass external ID for the secondary role when required.

[Ompragash]

plugins/s3 was extensively tested for the following scenarios, and the behavior works as expected:

• Using AWS access key and secret key. (without cross account access). :white_check_mark: Execution Link
• Using AWS access key and secret key. (with cross account access). :white_check_mark: Execution Link
• Assume IAM role on Delegate. (without cross account access). :white_check_mark: Execution Link
• Assume IAM role on Delegate. (with cross account access). :white_check_mark: Execution Link
• Using IRSA (without cross account access). :white_check_mark: Execution Link
• Using IRSA (with cross account access). :white_check_mark: Execution Link
• Use OIDC :white_check_mark: Execution Link

These changes also include fixes for both CI-14887 and CI-14134