Readability improvements 2/Inf

[Michal-MK]

Kotlinization

• converted ICommandHandler and SubCommandHandler to Kotlin
• removed registerSubCommands(), registration is done in constructor

LPBlocks

• unified style with LPItems

ItemIdentifier

• moved private fields to the top private helper classes to the bottom + added doc
• renamed interface to better convey what it does
• extracted magic constant to const field
• renamed 'r', 'k', and 'd' to meaningful strings
• fixed the comment to actually display in IDEA
• renamed getIgnoringData to getIgnoringDamage as the function was equal to getIgnoringNBT but damage was the determining thing, getUndamaged is a mystery to me
• all debug* and equals/hashCode stay at the bottom
• ItemStackAddInfo can be private just like it's fluid counterpart

General

• formatting to match what I am seeing the most