Storage-engine private data area per physical table

We need a data area per physical table where storage engine can store anything it wants.
Additionally, this should store engine_options, tablefile path, etc. It cannot be directly in the TABLE_SHARE, because partitions have different paths and engine_options.

We cannot directly backport MySQL WL#4305 (see the link below), because it was reverted by Oracle and, anyway, it doesn't solve the problem of different paths and engine_options.