* lisp/progmodes/sql.el

* lisp/progmodes/sql.el
(sql-is-sqli-buffer-p): New function.
(sql-generate-unique-sqli-buffer-name): Refactor and use it.
(sql-product-interactive): Simplify name logic.
* test/lisp/progmodes/sql-tests.el
(sql-tests-placeholder-filter-harness): New macro.
(sql-tests-placeholder-filter-simple)
(sql-tests-placeholder-filter-ampersand)
(sql-tests-placeholder-filter-period): Refactored tests and use macro.
(sql-tests-buffer-naming-harness): New macro.
(sql-tests-buffer-naming-default)
(sql-tests-buffer-naming-multiple)
(sql-tests-buffer-naming-explicit)
(sql-tests-buffer-naming-universal-argument)
(sql-tests-buffer-naming-existing): New tests.