Fix RITA clean 'no such command "scale"' error

[Zalgo2462]

If the scale field appears before dbStats when asking MongoDB the size of a collection, the command will fail. The RITA clean command stores this query document using bson.M which does not guarantee the order of the fields. As a result, the command will fail at random. This PR ensures that RITA uses bson.D to store this query document. This preserves the order of the fields each time the code is executed.

Fixes #770

Example mongo shell output:

> db.getSiblingDB("testdb-2022-11-21").runCommand({ "scale": 1024 * 1024, "dbStats": 1})
{
        "ok" : 0,
        "errmsg" : "no such command: 'scale'",
        "code" : 59,
        "codeName" : "CommandNotFound"
}
> db.getSiblingDB("testdb-2022-11-21").runCommand({"dbStats": 1, "scale": 1024 * 1024})
{
        "db" : "testdb-2022-11-21",
        "collections" : 11,
        "views" : 0,
        "objects" : 1017028,
        "avgObjSize" : 762.0969314512481,
        "dataSize" : 739.1680889129639,
        "storageSize" : 244.2265625,
        "numExtents" : 0,
        "indexes" : 59,
        "indexSize" : 95.8359375,
        "scaleFactor" : 1048576,
        "fsUsedSize" : 1208142.41015625,
        "fsTotalSize" : 1625364.50390625,
        "ok" : 1
}

[lisaSW]

tested