2.4.1_MODFEST.02

• Adds ability to recompress chunks into any supported format
• Adds overlay showing the size of chunks in bytes
• Adds overlay showing how much padding is produced inside the mca format for each chunk
• Adds overlay that tells you if a chunk exists (this is useful together with the "sum selection" feature to count how many chunks there are)
• Removes checksums from zstd writing
• Adds a small hidden feature, if you set MF_MCA_SELECTOR_FORCE_EXTERNAL=true as an environment variable, any chunk written will be written as an external .mcc file. No matter the size