Deprecate opendistro in API requests and responses

[shikharj05]

Is your feature request related to a problem? https://github.com/opensearch-project/security/issues/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

APIs impacted-

https://opensearch.org/docs/latest/security/access-control/api/#create-user

PUT _plugins/_security/api/internalusers/<username>
{
  "password": "kirkpass",
  "opendistro_security_roles": ["maintenance_staff", "database_manager"],
  "backend_roles": ["role 1", "role 2"],
  "attributes": {
    "attribute1": "value1",
    "attribute2": "value2"
  }
}

https://opensearch.org/docs/latest/security/access-control/api/#patch-user

PATCH _plugins/_security/api/internalusers/<username>
[
  {
    "op": "replace", "path": "/backend_roles", "value": ["klingons"]
  },
  {
    "op": "replace", "path": "/opendistro_security_roles", "value": ["ship_manager"]
  },
  {
    "op": "replace", "path": "/attributes", "value": { "newattribute": "newvalue" }
  }
]

[cwperks]

[Triage] Thank you for filing this issue Shikhar. Can we add the APIs that would be affected by the change and the names of the fields to the PR description?