feat(optimizer)!: PIVOT qualify with alias + type annotation

[geooo109]

More robust qualify + type annotation for PIVOT

[github-actions]

SQLGlot Integration Test Results

Comparing:

• this branch (sqlglot:geooo109/pivot_types, sqlglot version: geooo109/pivot_types)
• baseline (main, sqlglot version: 0.0.1.dev1)

By Dialect

dialect	main	sqlglot:geooo109/pivot_types	transitions	links
bigquery -> bigquery	24647/24652 passed (100.0%)	23497/23497 passed (100.0%)	No change	full result / delta
bigquery -> duckdb	867/1154 passed (75.1%)	0/0 passed (0.0%)	Results not found	full result / delta
duckdb -> duckdb	5823/5823 passed (100.0%)	0/0 passed (0.0%)	Results not found	full result / delta
snowflake -> duckdb	1129/1935 passed (58.3%)	0/0 passed (0.0%)	Results not found	full result / delta
snowflake -> snowflake	65133/65133 passed (100.0%)	63027/63027 passed (100.0%)	No change	full result / delta
databricks -> databricks	1370/1370 passed (100.0%)	1370/1370 passed (100.0%)	No change	full result / delta
postgres -> postgres	6042/6042 passed (100.0%)	6042/6042 passed (100.0%)	No change	full result / delta
redshift -> redshift	7101/7101 passed (100.0%)	7101/7101 passed (100.0%)	No change	full result / delta

Overall

main: 113210 total, 112112 passed (pass rate: 99.0%), sqlglot version: 0.0.1.dev1

sqlglot:geooo109/pivot_types: 101037 total, 101037 passed (pass rate: 100.0%), sqlglot version: geooo109/pivot_types

Transitions:
No change

Dialect pair changes: 0 previous results not found, 3 current results not found

✅ 42 test(s) passed