Reject policy with comma in name

[jinapurapu]

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Description

Adds check to throw error if policy name contains comma.

Motivation and Context

Policy lists are comma delimited, so policy names may not contain commas. Before, mc allowed creation of policy with comma in name.

How to test this PR?

Attempt to create a policy with a comma in the policy name.

/mc admin policy create minio "testPolicy,withcomma" ~/mytestpolicy.json
mc: <ERROR> Only a single policy may be specified here. policy name may not include comma.

Types of changes

• [ x] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Unit tests added/updated
• Internal documentation updated
• Create a documentation update request here

[taran-p]

This change looks fine, but should we add it on the server side instead? That way the user gets a consistent error in console as well as mc

[taran-p]

Actually, creating a policy with a comma in console doesn't actually fail, it just creates a broken policy so this should definitely be added server side

[cniackz]

We should not support policy names with commas.