SPL Token-2022 - v0.6.0

Summary of changes

• Check expected new source ciphertext in processing confidential transfer [ZELLIC 3.1] by @samkim-crypto in #3867
• Divide encrypted fee into lo and hi (TOB-STK-11) by @samkim-crypto in #3878
• Fix parenthesis typo in fee calculation doc by @samkim-crypto in #3928
• Fix ceil_div variable name by @samkim-crypto in #3935
• Restrict InitializeMint and UpdateMint instructions by @samkim-crypto in #3938
• Use OptionalNonZeroPubkey and OptionalNonZeroEncryptionPubkey for confidential extension by @samkim-crypto in #3943
• Rename ops to syscall for better readability by @samkim-crypto in #3944
• Fix non-transferable extension for unchecked transfers by @joncinque in #4005
• Add confidential transfer authority type by @samkim-crypto in #4025

Full Changelog: token-2022-v0.5.0...token-2022-v0.6.0

NOTE: This is still an alpha release, so backwards incompatible changes are possible in the future. Do not depend on the exact layout of extension data for your code.