fix(secure-onboarding) Fix resource update operation

[ravinadhruve10]

The TF provider’s knowledge of cloud account object is older and different from the actual BE cloud account. This is because BE has modified the account object with fields like organization_id during org onboarding. Hence, during intended PUTs, TF overwrites these fields resulting in unexpected state.

Fix summary:

1. Add and expose the organization_id in provider's account resource schema (as a computed field only). This is to let the customers know if their onboarded account is part of any org when they fetch the real existing infrastructure objects using GET calls.
2. During resource updates (PUT API calls) restrict and reject with error when the customer tries to update any non-updatable resource fields.
3. Minor refactoring for cleaner code.

Testing done:

Validated the scenarios :-

• During tf apply again --> it returns and updates organization_id on the account.
• No unnecessary PUTs
• On triggering an intended PUT :-
  • restricts any non-updatable fields
  • PUT works as expected, doesn't overwrite organization_id to ""

[ravinadhruve10]

The secure acceptance test failing in the CI above is not related to this PR or resource: --- FAIL: TestAccDataUser (1.87s) which is flaky because in the rerun it passed, and another test fails instead :-

=== NAME  TestAccCustomRoleResource
    resource_sysdig_custom_role_test.go:17: Step 4/5 error: Check failed: Check 1/1 error: sysdig_custom_role.custom-role: Attribute 'name' expected "custom-role-67c8gramz1-updated", got "custom-role-67c8gramz1"
--- FAIL: TestAccCustomRoleResource (10.20s)

The acceptance tests related to resources in this PR have all passed.