Add WithColour, WithAxis, and WithFacing in blocks

[AkmalFairuz]

Introduces WithColour, WithAxis, and WithFacing support for blocks so we can properly handle state-aware transformations in the WorldEdit server. The main use case is implementing a //rotate command that rotates selected regions while preserving block properties. Rotation only applies to blocks that depend on orientation, specifically those using Axis and Facing. By exposing these modifiers directly on the block interface, we can transform block states cleanly and deterministically during region edits without relying on hardcoded type switches.

Previously, the alternative approach relied on reflect to modify block state dynamically. That worked functionally, but the performance overhead was noticeable, especially when rotating large selections. Reflection adds unnecessary runtime cost and reduces type safety. With explicit WithAxis and WithFacing methods, rotation becomes faster.

Example:

for pos, b := range blocks {
  if a, ok := b.(block.HasFacing); ok {
    b = a.WithFacing(targetFace)
    tx.SetBlock(pos, b)
  }
}