testing of "partition attributes" changes

includes commits

06eeabbb5c1 fix printing of per-partition engine options

a5b41b05ba2 MDEV-37815 connect_string in partitioning is broken

d0af15f55d3 MDEV-37815 field and index engine attributes in partitioning are broken

032688116f2 MDEV-37815 table engine attributes in partitioning is broken

d76113eb6b3 cleanup: partition_element_iterator

8a71872fc8d cleanup: remove HTON_CAN_READ_CONNECT_STRING_IN_PARTITION

879fcfc068e parsing of table/index/field attributes: auto-alias all boolean values

User visible changes:

• per-partition engine defined attributes are now shown in SHOW CREATE TABLE similar to per-table engine defined attributes.
• CONNECTION is rejected for those engines that don't support it (unless IGNORE_BAD_TABLE_OPTIONS is enabled)
• CONNECTION is stored in .frm (and .par) files differently from before. Old tables are supported of course.
• field and index engine defined attributes can be specified for partitioned tables
• every table/field/index engine defined attribute that recognized values YES and NO now supports full set of boolean aliases (TRUE/FALSE/ON/OFF/0/1). For example ENCRYPTED=ON.
• DROP/ALTER SERVER must be followed by FLUSH TABLES (MDEV-37827)