[Blueprints] Support multiline SQL queries in the runSql step

[adamziel]

Adapts WP_MySQL_Naive_Query_Stream to support multiline SQL queries in the runSql step. With this PR, the following call works:

await runSql(php, {
	sql: new File(
		[
			`SELECT * FROM 
				wp_users
				-- users table
			;
			 SELECT * FROM wp_posts;`
		]
		'no-trailing-newline.sql'
	),
});

Whereas before this PR, the runSql step assumed every line of a SQL file is a separate query and would fail on the above call.

Implementation details

See WordPress/sqlite-database-integration#264. Tl;dr we tokenize the query and treat ; and EOF tokens as query separators. The stream is only "naive" in that every query must be smaller than 15MB. It might fail for some very large WordPress posts, but should work most of the time. Once the lexer provides an explicit distinction between syntax errors and incomplete input, we'll be able to support arbitrarily large queries.

Testing Instructions (or ideally a Blueprint)

Tests have been updated to verify multiline query handling, SQL comment preservation, and queries with subqueries. The streaming parser correctly handles edge cases like empty lines, semicolon-only lines, and queries split across chunk boundaries.

cc @JanJakes