fix(tianmu): backport ALTER table xxx ADD numeric column return error(#1734)

[chenshengjiang]

Summary about this PR

Issue Number: close #1734

1.Add test case: when alter table xxx add colmn operation is failed firstly, executing
alter table xxx add column by successful case again
2. Delete the temporary directory to solve the copy problem

Tests Check List

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Changelog

• New Feature
• Bug Fix
• Performance Improvement
• Build/Testing/CI/CD
• Documentation
• Not for changelog (changelog entry is not required)

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features

[mergify]

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