Third part of fix for bug#25722927 "NEWDD FK: ALTER TABLE CHANGE COLUMN TYPE SHOULD CHECK FK CONSTRAINT" [noclose]

After we have started to store information about foreign keys in the
Transactional Data Dictionary it became possible to move checks of
foreign key definition validity from the storage engine to SQL-layer
and thus reduce code duplication and simplify SE implementation.

This patch replaces usage of handler::can_switch_engines() method to find
out if table participates in any foreign key with direct use of dd::Table
or TABLE_SHARE objects. Since handler::can_switch_engines() method is
not used for anything else in current server it was removed from SE API
and few engines which implemented it.

Generic error code and message which were issued when one tries to change
SE for table participating in a foreign key have been replaced with new
more specific ones. Existing test coverage was adjusted accordingly.