[OTDB-4089] Storage Group add attribute "number of Virtual Storage Groups"

[GuanchuShen]

Description

Different storage groups are supported with different number of virtual storage groups.

Content1 ...

1. Support SQL，e.g. create storage group root.sgc virtualstoragegroupnum = 8;

Content2 ...

2. Enhanced "show storage group" SQL statement，e.g. show storage group; This SQL statement can display two columns: storage group, virtual storage group num.

Content3 ...

3. Compatible with older version of mlog(without virtual storage group num).

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This PR has:

• been self-reviewed.
  • concurrent read
  • concurrent write
  • concurrent read and write
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods.
• added or updated version, license, or notice information
• added comments explaining the "why" and the intent of the code wherever would not be obvious
  for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold
  for code coverage.
• added integration tests.
• been tested in a test IoTDB cluster.

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Key changed/added classes (or packages if there are too many classes) in this PR