db: DB.SSTables misreports virtual table properties

[jbowens]

It just blindly reports the properties of the underlying backing sstable. I think we should use GetScaledProperties and include just the scaled CommonProperties for virtual tables.

pebble/db.go

Lines 2250 to 2264 in ae9f98c

	if opt.withProperties {
	p, err := d.fileCache.getTableProperties(
	m,
	)
	if err != nil {
	return nil, err
	}
	destTables[j].Properties = p
	}
	destTables[j].Virtual = m.Virtual
	destTables[j].BackingSSTNum = m.FileBacking.DiskFileNum
	objMeta, err := d.objProvider.Lookup(base.FileTypeTable, m.FileBacking.DiskFileNum)
	if err != nil {
	return nil, err
	}

Jira issue: PEBBLE-409