Deprecate opendistro in API requests and responses

[shikharj05]

Is your feature request related to a problem?
#5092
The security repo has lingering usages of the legacy terms like opendistro_security is API requests and responses, these should be replaced with opensearch_security, however legacy API contracts are not explicitly marked as deprecated. This task is to track marking opendistro API request/responses as deprecated.

What solution would you like?
Mark opendistro API requests/responses as deprecated, removal in a next major version. Replace with opensearch - for e.g. opendistro_security_roles in Create User - https://opensearch.org/docs/latest/security/access-control/api/#create-user