feat: update workspace util func and fix known bug

[healthjyk]

…ce dir is not hidden folder

What type of PR is this?

/kind feature

What this PR does / why we need it:

1. add CURD func by default workspace operator;
2. use inline for the GenericObjectStorageConfig for OssConfig and S3Config;
3. correct validation for S3Config.

[coveralls]

Pull Request Test Coverage Report for Build 7167478622

• 4 of 52 (7.69%) changed or added relevant lines in 2 files are covered.
• 6 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.4%) to 74.094%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/workspace/validation.go	0	1	0.0%
pkg/workspace/operator.go	4	51	7.84%

Files with Coverage Reduction	New Missed Lines	%
pkg/engine/operation/watch.go	1	85.93%
pkg/workspace/operator.go	5	51.63%

Totals
Change from base Build 7162380829:	-0.4%
Covered Lines:	6870
Relevant Lines:	9272

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💛 - Coveralls

[SparkYuan]

What is the pkg/workspace/testdata/invalid_workspaces_dir/dir_workspace_file/.gitkeep file used for?

[SparkYuan]

lgtm