Defragmentation should handle ChunkTooBig errors

Currently, the defragmentation policy is sending moveChunk commands with forceJumbo set to true. This is in the case that our datasize calculation is incorrect and the chunk we decide to move is very large. However, we don't actually want to move huge chunks for defragmentation, as we are trying to move small chunks only.

Instead of sending the request with forceJumbo set to true, we should handle the ChunkTooBig and ExceededMemoryLimit errors to not retry these migrations.