Drop & drag roomtiles in roomlist fails if you have too many or too much ordering

[ara4n]

I suspect this is an artefact of the stupid floating point ordering system its currently using.

[ara4n]

combined with #2365 this makes the drop & drag feel incredibly flakey.

[ara4n]

@intelfx was suffering this; his tag orderings are:

$ grep -B1 '"order":' data
                                    "m.favourite": {
                                        "order": null
--
                                    "m.favourite": {
                                        "order": 0.9921875
--
                                    "m.favourite": {
                                        "order": 0.9521484375
--
                                    "m.favourite": {
                                        "order": null
--
                                    "m.favourite": {
                                        "order": null
--
                                    "m.favourite": {
                                        "order": 0
--
                                    "m.favourite": {
                                        "order": 0.9160156250000001
--
                                    "m.favourite": {
                                        "order": 0.98828125
--
                                    "m.favourite": {
                                        "order": ".046875"

Looks like this is an unpleasant combo of string v. float typing, 0's and nulls.

[ara4n]

clearly different clients are maintaining it differently and then interacting badly.

[turt2live]

The room list also doesn't scroll when dragging and dropping. This makes it difficult to sort rooms when using custom tags.

[turt2live]

Closing in favour of #8614