Implement client validation

[sigalsax]

For the CLI/SDK, there are cases where we should catch invalid input at the client-level. That way, amongst other things, we can provide more meaningful feedback to our users should they input wrong or unexpected data. This will avoid errors like 500 server errors for example that don't provide meaningful information for how to overcome them, won't be returned to the user

For example: Allowing users to provider strings for flags that should be integers. conjur list --limit=s or --offset=s. If a user provides incompatible types that will fail at the server level, we should catch them at the client and not relay on the server. For example, a valid error message would be "'offset' contains an invalid value. 'offset' must be an integer greater than or equal to 0"

DOD

• [ ] Map out areas where we can implement client validation and create a design (can be a paragraph) for how to address this
• [ ] Implement the client validation