Add FROM-first query syntax support

[Abdelrahman-358]

Description

This PR implements support for the feature proposed in #17336 by introducing FROM-first query syntax.

Usage Examples

-- Current syntax
SELECT temperature, humidity FROM sensors WHERE time >= 10;

-- FROM-first syntax
FROM sensors SELECT temperature, humidity WHERE time >= 10;

-- Quick exploration (omitting SELECT implies SELECT *)
FROM sensors LIMIT 10;

Implementation Approach

1. Grammar Update
   Add fromFirstQuerySpecification rule to RelationalSql.g4.

2. AST Builder
   Add visitFromFirstQuerySpecification() in AstBuilder.java, reusing the existing visitQuerySpecification() logic, with handling for the omitted SELECT clause (interpreted as SELECT *).

3. Testing
   Add unit and integration tests to cover the new syntax scenarios.

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This PR has:

• been self-reviewed.
• 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