[DocDB] get_clients.sh doesn't support installing aarch64 clients

[iSignal]

Jira Link: DB-539

Description

https://docs.yugabyte.com/preview/admin/ysqlsh/ documents a get_clients.sh script which downloads a yugabyte-client tar.gz. Now that we build aarch64 for the db,

1. we should also build the client package for aarch64 and
2. let this script detect the right package to download based on the arch.

@FranckPachot @jharveysmith

[sharkberto]

Right now, my understanding these client packages are set to be created on an as-needed basis; I am going to remove "Client Package" from release checklist, as i've not had any requests during the release process to create a client package. If there is an automation set to be created any time soon, please keep me in the loop