### What problem does this PR solve?

1. Enable periodical cleanup
2. Cleanup decides which items to clean by the drop timestamp of the
items, but the drop timestamp is not correct.
3. Skip removing empty files of fulltext index

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

We should only clean up empty directories instead of empty files.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

## Summary
This PR replaces `OPTIMIZE IDENTIFIER` syntax with `ALTER IDENTIFIER` to
better align with SQL standards

## Changes
- Modified corresponding grammar rules in the parser
- Modified corresponding logical and physical operators
- Modified corresponding test code

---------

Signed-off-by: jinhai <[email protected]>
Co-authored-by: jinhai <[email protected]>

### What problem does this PR solve?
Issue:
In the following scenario, cleanup txn cleans the table dropped, but the
entities are still needed by optimize.

```
*--Optimize------------------------------------------------------
              * -Drop table-*    *-Checkpoint-*   *-Cleanup-*
```

Solution:
We will only clean up entities dropped before both the begin timestamp
of active transactions and the latest checkpoint, ensuring the entities
are no longer needed.
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

CPack TGZ


### Type of change

- [x] Other (please describe): CI

### What problem does this PR solve?

There is error "No such file or directory [/var/infinity/wal/wal.log'"
sometimes on unit test, mount /var/infinity to check the file on error
next time.

### Type of change

- [x] Other (please describe): tests.yml

### What problem does this PR solve?

To detect why the wal.log is missing.

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <[email protected]>

### What problem does this PR solve?

heap-buffer-overflow occurs while calling AddCacheInfo(). It seems 2
threads are writing to vector at the same time.

```
   #5 0x560339e634b5 in infinity::NewTxn@infinity_core::AddCacheInfo(std::shared_ptr<infinity::CacheInfo@infinity_core> const&) /infinity/src/storage/new_txn/new_txn_impl.cpp:5474:88
    #6 0x560338c97366 in infinity::SegmentMeta@infinity_core::LoadFirstDeleteTS() /infinity/src/storage/catalog/meta/segment_meta_impl.cpp:157:28
```

### Type of change

- [ ] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

delete_ut.cpp failed with error "wal.log is not found" intermittently. 

At the end of the testunit, db directory is removed explicitly. At the
same time wal manager is still working in NewFlush().
wal.log is needed in NewFlush().
We should not call RemoveDbDirs() at the end of the testunit, db
directory will be cleaned in TearDown().

### Type of change

- [x] Test cases

### What problem does this PR solve?

Restart test failed on test_insert.py::TestInsert::test_index with error
"Unhandled Exception: Chunk index row alignment error" occasionally, add
more pd to help analyze the issue .

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

restart_test/test_insert.py::TestInsert::test_index in slow test failed
intermittently.

* ------checkpoint----- append ------- checkpoint-------
*--------------------------------------------------   |
*--------------------------------------------------   killed

During the first checkpoint, it persists block data to obj in pm.
append updates the block data.
During the 2nd checkpoint, it removes the old obj from pm and persists
block data to new obj in pm.
The error occurs when instance is killed after old obj is removed from
pm but new obj is not written.

We should persists block data to new obj in pm and then remove old obj
from pm during Persist().

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Fix compilation on AVX512


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

### What problem does this PR solve?

Update version info to 0.6.2

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

Signed-off-by: Jin Hai <[email protected]>

### What problem does this PR solve?

Create optimize processor to execute both periodical triggered optimize
operation and manual optimize command.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Refactoring

### What problem does this PR solve?

After each test, we expect infinity*.profraw is generated completely
within 30s.
If infinity*.profraw is still empty after 30s, log it and do not exit
with error.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

Implemented snapshot management APIs in **http_api_reference.mdx** and
**pysdk_api_reference.md**, including **create_table_snapshot**,
**restore_table_snapshot**, and **drop_snapshot**.

---------

Signed-off-by: jinhai <[email protected]>
Co-authored-by: jinhai <[email protected]>

### What problem does this PR solve?

1) Add python, http interface for alter index
2) Add http interface for dump index
3) Modify testcases and docs

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Documentation Update
- [x] Test cases