Salvage tests and fix a leak found in another review: see https://gitlab.winehq.org/wine/wine/-/merge_requests/897#note_9175 points 1 and 2. 3. is why !897 was reverted.
This does not contain the (incorrect) changes to VariantCopyInd, but instead fixes the leak identified in VariantClear (VT_RECORD needs to free pvRecord), and the wrong allocator being used in VariantCopy (it should have been IMalloc, rather than `HeapAlloc`, as shown by the fact IMallocSpy observes these allocations).
This also cleans up some dubious behavior by the test IRecordInfoImpl, which was modifying a VARIANT that it did not own or receive as an argument in the middle of VariantClear. This was likely undefined behavior, and in any case concealed the heap leak.