Restrict creds user receives upon login to cloud-gate based on need

[ssuresh1750]

Issue

Currently, on logging in to cloud-gate, a user receives credentials for all of the accounts that they have access to.

Steps to reproduce

Login to cloud-gate on UI or via CLI.

Impact

Even though these are short lived credentials, they should be granted on a need/per request basis instead of giving all the creds. This way a user is only given creds to a particular account/role instead of all roles. Restricting creds on a need/request basis is good from an attack surface perspective.

Remediation

Would be good to grant only the credentials that were requested by the user for both the CLI and the UI.