Add support for < 1 bocks-per-tick build-speed.

[andrepl]

There is currently no way to build slower than 1 block per tick. supporting a float value here would be handy, but the BuildManager will need to learn to handle that.

[SonarBeserk]

i suggest making it possible to increase the tick interval between placing vs making less of blocks being placed

[andrepl]

that's essentially how it would work, but there is only one buildmanager, and it still fires every tick, so it would increment a counter by 0.1 instead of 1 for example, which would cause that particular build job to only place a block every 10th run.