[#2127] Improvement(core): improve TreeLock for ease of unlock and fix unexpected err when lock failed

[YxAc]

What changes were proposed in this pull request?

• improve TreeLock for ease of unlock by keeping lock type
• fix unexpected err when lock failed and unlock all nodes that have been locked

Why are the changes needed?

Fix: #2127

Does this PR introduce any user-facing change?

N/A

How was this patch tested?

UT

[yuqi1129]

@YxAc
Can you add some tests about the scenario when the method lock fails (throws exceptions) and everything is still okay, that is: we can unlock the nodes that have been locked. You can mock the lock method and do some corresponding tests for it. There are some similar tests in the TestLockManager, you can refer to them.

[YxAc]

@YxAc Can you add some tests about the scenario when the method lock fails (throws exceptions) and everything is still okay, that is: we can unlock the nodes that have been locked. You can mock the lock method and do some corresponding tests for it. There are some similar tests in the TestLockManager, you can refer to them.

done

[yuqi1129]

It's okay with me, @jerryshao . Could you spare some time to take a look?

[jerryshao]

LGTM, Thanks @YxAc for your contribution.