Snowflake: Fix ScalingPolicy and WarehouseType Refs in WarehouseObjectProperties and use ObjectReferenceSegment in AlterWarehouseStatementSegment

[moreaupascal56]

Brief summary of the change made

As talked in the issue there is 2 distinct issues:

• Fix ScalingPolicy and WarehouseType Refs in WarehouseObjectProperties : The main issue was that SCALING_POLICY can be quoted (cf ALTER WAREHOUSE Snowflaken statements do no support variables or single quotes #4937) and that was not dealt with.
  I changed the way SCALING_POLICY works in WarehouseObjectPropertiesSegment to mimic how WarehouseSize is working.
  Doing that I saw that there is a new WAREHOUSE_TYPE in the snowflake docs (SNOWPARK-OPTIMIZED) so I did the same work for WarehouseType.
  
  Then I udpated the tests accordingly.
• Replace NakedIdentifierSegment by ObjectReferenceSegment in AlterWarehouseStatementSegment: As said in the issue we can use variable for names (why not) and so I replaced NakedIdentifierSegment by ObjectReferenceSegment and added a test

fixes #4937

Are there any other side effects of this change that we should be aware of?

Pull Request checklist

• Please confirm you have completed any of the necessary steps below.

• Included test cases to demonstrate any code changes, which may be one or more of the following:

  • .yml rule test cases in test/fixtures/rules/std_rule_cases.
  • .sql/.yml parser test cases in test/fixtures/dialects (note YML files can be auto generated with tox -e generate-fixture-yml).
  • Full autofix test cases in test/fixtures/linter/autofix.
  • Other.

• Added appropriate documentation for the change.

• Created GitHub issues for any relevant followup/future enhancements if appropriate.

[coveralls]

coverage: 100.0%. remained the same when pulling b931279 on moreaupascal56:alter-warehouse-fix-optionnaly-quoted-set into 8e14e5a on sqlfluff:main.

[github-actions]

Coverage Results ✅

Name    Stmts   Miss  Cover   Missing
-------------------------------------
TOTAL   16743      0   100%

222 files skipped due to complete coverage.

[greg-finley]

Nice!