iam_role - delete inline policies, stabilize for migration to amazon.…

…aws (ansible-collections#1054)

iam_role - delete inline policies, stabilize for migration to amazon.aws

SUMMARY
Stabilize for migration to amazon.aws

delete inline policies before deleting the role
removed global vars and refactored function definitions
added some extra integration tests for check mode

ISSUE TYPE

Feature Pull Request

COMPONENT NAME
iam_role

Reviewed-by: Markus Bergholz <[email protected]>
Reviewed-by: Joseph Torcasso <None>
Reviewed-by: Alina Buzachis <None>
Reviewed-by: Jill R <None>