Fix metric view YAML comment field ordering (#402)

[jacksandom]

Summary

• Fixes METRIC_VIEW_INVALID_VIEW_DEFINITION error when creating metric views with a comment field
• Swaps comment and source ordering in YAML generation and all documentation/test examples

Closes #402

Problem

_build_yaml_block() generated YAML with comment before source, but the Databricks parser expects source at index 1 (right after version). Any metric view created with a comment would fail with:

METRIC_VIEW_INVALID_VIEW_DEFINITION: Missing required creator property 'source' (index 1)

Changes

File	Change
databricks-tools-core/.../unity_catalog/metric_views.py	Swap source before comment in _build_yaml_block()
databricks-skills/databricks-metric-views/SKILL.md	Fix 2 YAML examples
databricks-skills/databricks-metric-views/patterns.md	Fix 4 YAML examples
.test/skills/databricks-metric-views/ground_truth.yaml	Fix 5 expected YAML strings

Test plan

• Verified generated YAML outputs version then source then comment ordering
• Smoke tested metric view creation with comment on workspace
• Grep confirmed no remaining top-level comment-before-source instances across all 4 files