feat(sql): add delete() method to SQLBackend

[jsouzadasilva]

This PR addresses the issue: #11205.

Adds a delete() method to SQLBackend for conditionally removing rows from tables, following the established insert()/upsert() patterns. The where parameter is required — passing None raises IbisInputError directing users to truncate_table() instead. Includes a BigQuery-specific override for catalog/database resolution matching the existing insert/upsert pattern.

The API design look like this:

con.delete("table_name", ibis._.salary > 200)
con.delete("table_name", lambda t: (t.run_datetime == val) & (t.run_id == rid))
con.delete("table_name", ibis._.run_id == "abc123", database="catalog.database")

We've tested the BigQuery delete locally against our GCP project and BigQuery dataset, using a simple python script. Here's a summary of the tests run:

• test_1_delete_by_single_column
• test_2_delete_by_compound_condition
• test_3_delete_no_matching_rows
• test_4_delete_with_deferred
• test_5_delete_with_database_param
• test_6_delete_where_none_raises

[dtran-im]

@cpcloud Hello again. Wondering if you would approve the full test suite to run on this PR?