Add "AggregatedSnapshotCapacityInMb" to CnsSnapshotCreateResult and CnsSnapshotDeleteResult.

[lipingxue]

Description

This change is to add "AggregatedSnapshotCapacityInMb" to CnsSnapshotCreateResult and CnsSnapshotDeleteResult.

Type of change

Please mark options that are relevant:

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update
• [ ] Build related change

How Has This Been Tested?

Run unit test. In the unit test result, field "AggregatedSnapshotCapacityInMb" is available in CnsSnapshotCreateResult and CnsSnapshotDeleteResult

client_test.go:355: Creating snapshot using the spec: []types.CnsSnapshotCreateSpec{
            {   
                VolumeId: types.CnsVolumeId{
                    Id: "1cf88bdc-0b1d-4198-b995-50319ed6865d",
                },
                Description: "example-vanilla-block-snapshot",
            },      
        }       
    client_test.go:379: snapshotCreateResult: &types.CnsSnapshotCreateResult{
            CnsSnapshotOperationResult: types.CnsSnapshotOperationResult{},
            Snapshot:                   types.CnsSnapshot{
                SnapshotId: types.CnsSnapshotId{
                    Id: "c517f616-68fe-4dfb-a5e2-f022584139cd",
                },
                VolumeId: types.CnsVolumeId{
                    Id: "1cf88bdc-0b1d-4198-b995-50319ed6865d",
                },
                Description: "example-vanilla-block-snapshot",
                CreateTime:  time.Now(),
            },
            AggregatedSnapshotCapacityInMb: 0,
        }   

 client_test.go:512: Deleting snapshot using the spec: []types.CnsSnapshotDeleteSpec{
            {   
                VolumeId: types.CnsVolumeId{
                    Id: "1cf88bdc-0b1d-4198-b995-50319ed6865d",
                },  
                SnapshotId: types.CnsSnapshotId{
                    Id: "c517f616-68fe-4dfb-a5e2-f022584139cd",
                },
            },  
        }       
    client_test.go:536: snapshotDeleteResult: &types.CnsSnapshotCreateResult{
            CnsSnapshotOperationResult: types.CnsSnapshotOperationResult{},
            Snapshot:                   types.CnsSnapshot{
                SnapshotId: types.CnsSnapshotId{
                    Id: "c517f616-68fe-4dfb-a5e2-f022584139cd",
                },
                VolumeId: types.CnsVolumeId{
                    Id: "1cf88bdc-0b1d-4198-b995-50319ed6865d",
                },
                Description: "example-vanilla-block-snapshot",
                CreateTime:  time.Now(),
            },
            AggregatedSnapshotCapacityInMb: 0,
        }

Checklist:

• [ ] My code follows the CONTRIBUTION guidelines of this project
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged