Impl removedByPlayer and canHarvestBlock in IForgeBlock

[rikka0w0]

getExpDrops will be always called for all blocks, the exp orb drop behavior follows this rule:

        //          isVanillaBlock      exp     Action
        //  Vanilla     true            xxx     Let the vanilla method do the orb drop
        //  Fabric mod  false           == 0        Let the vanilla method do the orb drop
        //  Forge mod   false           >0      Do orb drop here
        //  Forge mod   false           <=0     Do nothing

Fabric mods does not have a method to get the amount of experience dropped from another block. If a Forge mod calls getExpDrop on a Fabric mod block, it will always get 0. This will be changed once Fabric has something equivalent.

getHarvestTool and getHarvestLevel are stubs, I will impl more tooltype stuff in another pr.

[rikka0w0]

The logic here is somewhat tricky, but looks sound.

If #127 ends up merged before this, can you include the implementation of ForgeHooks.canHarvestBlock?

Yes of course, and also there are other things that I'm going to add to ForgeHooks and ForgeHooksClient. In all of my PRs, the event dispatch is handled by individual classes, and ForgeHooks is only supposed to be used for accepting Forge mod calls.

[TheGlitch76]

Merge conflicts!