Add --endpoint parameter to osc-cli

[garnierclement]

Hello, Would it be possible to add --endpoint parameter to osc-cli (like aws cli). First use case is when you start on Outscale and you first need to collect your AK/SK with osc-cli icu ListAccessKeys that requires email/password authentication. To do so, you need to create an empty profile with no AK/SK simply to configure region endpoint, not very straightforward. It is useful to request some API method that does not require authentication (i.e. catalogs on different regions). Thanks.