[Bug]: [privilege_group] The interface "grant_v2" does not support empty collectionName while the error says it does

[binbinlv]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version: master-latest
- Deployment mode(standalone or cluster):both
- MQ type(rocksmq, pulsar or kafka):    all
- SDK version(e.g. pymilvus v2.0.0rc2): 2.5.0rc126
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

The interface "grant_v2" does not support empty collectionName while the error says it does

role.grant_v2("DatabaseReadOnly", "default", "binbin_new_1")
(code=65535, message=collectionName should be empty or * for the database level privilege: DatabaseReadOnly
role.grant_v2("DatabaseReadOnly", "default")
TypeError: grant_v2() missing 1 required positional argument: 'collection_name'
role.grant_v2("DatabaseReadOnly", "default", "")
code=1, message=`collection_name` value  is illegal

Expected Behavior

The interface "grant_v2" supports empty collectionName

Steps To Reproduce

from pymilvus import connections
from pymilvus import CollectionSchema, FieldSchema
from pymilvus import Collection
from pymilvus import connections
from pymilvus import DataType
from pymilvus import Partition
from pymilvus import utility
from pymilvus import MilvusClient
from pymilvus import Role

connections.connect(host="***", user="root", password="Milvus")
client = MilvusClient(uri="http://***:19530", user="root", password="Milvus")
client.create_collection("binbin_new", dimension=128)
role = Role("binbin")
role.create()
utility.list_roles(True)
utility.create_user(user="user1", password="Milvus")
role.add_user("user1")
utility.list_roles(True)
role.list_grants()
role.grant_v2("DatabaseReadOnly", "default", "binbin_new_1")
role.grant_v2("DatabaseReadOnly", "default")
role.grant_v2("DatabaseReadOnly", "default", "")

### Milvus Log

_No response_

### Anything else?

_No response_

[binbinlv]

/assign @shaoting-huang

[sre-ci-robot]

@binbinlv: GitHub didn't allow me to assign the following users: shaoting-huang.

Note that only milvus-io members, repo collaborators and people who have commented on this issue/PR can be assigned. Additionally, issues/PRs can only have 10 assignees at the same time.
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In response to this:

/assign @shaoting-huang

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[shaoting-huang]

/assign

[shaoting-huang]

after fix:

>>> role.grant_v2("ReadOnly", "default", "")
>>> role.list_grants()
GrantInfo groups:
- GrantItem: <object:Global>, <object_name:*>, <db_name:default>, <role_name:binbin>, <grantor_name:root>, <privilege:DatabaseReadOnly>