Hammer Asset Browser

Our asset browser is now usable in Hammer, it was there before for cloud models but now I've hooked everything up - selecting materials, drag data, Hammer specific asset context menus.

Once everyone is happy with it we'll switch the default over to this instead of legacy, so if there's something it can't do (that you need) please let us know.

I've also swapped a bunch of the asset pickers from the various native implementations to a unified one of our asset browser.

I won't show you another picture of the asset browser, but this basically lets you choose cloud assets through this in Hammer too.