Fix okta pagination handling on apps, groups, and users

[smoy]

What changed?

• Fixed pagination for okta list_applications, list_users, and list_groups

Rationale

• In pagination, the next_apps|users|groups is type list, instead of append to the existing list, we have to use extend

How was it tested?

If it was manually verified, list the instructions for your reviewers to follow.

• Unit Tests
• Functional Tests
• Manually Verified

This is a little tricky since our testing infra does not mock or have mechanism for testing okta pagination and okta test env has limit that does not trigger pagination.

[ashugart-hazel]

Validated fix. 🙌🏽

[castrapel]

LGTM!