This is helper to set proper tuple_format vtable depending on allocator
symbolic name.

Follow-up #5419

It is assumed to accumulate all allocation setting across all allocators
in order to unify Allocator::create() interface.

Follow-up #5419

Patch which prepare ability to select memory allocator.
Changed tuple allocation functions to templates, with
parameterized by the memory allocator type.
Part of #5419

Previously in memtx space direct memtx_tuple_new/memtx_tuple_delete
function calls were used. Also pointers to functions, used for alloc/free
memory for memtx tuples are stored in tuple_format_vtab. Replaced direct
memtx_tuple_new and memtx_tuple_delete function calls in memtx_space to
calls via pointers from vtab.
Part of #5419

Part of #5385