sql: Move box/sql-* tests to dedicated suite.

test/sql/sql-check-clear-ephemeral.result

test/sql/sql-check-clear-ephemeral.test.lua

test/sql/sql-clear.result

test/sql/sql-clear.test.lua

test/sql/sql-delete-multiple-idx.result

test/sql/sql-delete-multiple-idx.test.lua

test/sql/sql-delete.result

test/sql/sql-delete.test.lua

test/sql/sql-drop-index.result

test/sql/sql-drop-index.test.lua

test/sql/sql-drop-table.result

test/sql/sql-drop-table.test.lua

test/sql/sql-insert-unique.result

test/sql/sql-insert-unique.test.lua

test/sql/sql-max-on-index.result

test/sql/sql-max-on-index.test.lua

test/sql/sql-min-on-index.result

test/sql/sql-select-null.result

test/sql/sql-select-null.test.lua

test/sql/sql-transition.result