Fix bugs in JSON and SQA storage modules

[saitcakmak]

Summary:
Fix multiple bugs in ax/storage:

• Missing raise before SQADecodeError silently ignores JSON mismatches during copy_db_ids (sqa_store/utils.py:114)
• int(None) crash in SQA encoder: metric_registry.get() can return None, but the result was immediately passed to int() before the None check could run (sqa_store/encoder.py:393)
• AttributeError on None kwargs in JSON decoder: kwargs.pop() was called before the if kwargs is not None guard (json_store/decoder.py:1092)
• decode_args_list length mismatch in SQA save: used len(trials) instead of len(trials_to_reduce_state) and [...] * len(trials) instead of a single-element list (sqa_store/save.py:245,254)
• SQLAlchemy filter no-op: SQAExperiment.id is not None uses Python identity check instead of SQLAlchemy's .isnot(None) (sqa_store/load.py:760)
• Inconsistent threshold in error message: says "> 10" but the actual check is > 15 (sqa_store/utils.py:77)
• Garbled error message in with_db_settings_base.py: sentence fragments in wrong order (sqa_store/with_db_settings_base.py:106)
• Doubled path ax/ax/storage in error message (sqa_store/encoder.py:131)
• Backslash line-continuation inside string literal causes 16 extra spaces in error message (sqa_store/encoder.py:654)
• Missing space between concatenated strings (sqa_store/db.py)
• Typo "SCalarized" → "Scalarized" (sqa_store/encoder.py)
• Missing space in SKIP_ATTRS_ERROR_SUFFIX (sqa_store/utils.py)

Differential Revision: D92879499

[meta-codesync]

@saitcakmak has exported this pull request. If you are a Meta employee, you can view the originating Diff in D92879499.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 77.77778% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.79%. Comparing base (4b89d30) to head (a09d6fe).

Files with missing lines	Patch %	Lines
ax/storage/sqa_store/utils.py	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4893      +/-   ##
==========================================
- Coverage   96.80%   96.79%   -0.01%     
==========================================
  Files         595      595              
  Lines       63122    63123       +1     
==========================================
- Hits        61108    61103       -5     
- Misses       2014     2020       +6     

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